Essay on Chinua Achebes Things Fall Apart: Spiritual and Traditional A

Spiritual and Traditional Aspects of Things Fall Apart Chinua Achebe describes in his criminal record Things Fall Apart (1958) some interesting features of what life could look handle in an African village during late 19th century. The society that the Nigerian author presents is in most ways considerably different from our westbound society of today. Life in the African village of Umuofia was, among many separate things, spiritual and traditional. The spiritual aspect of life in Umuofia is well illustrated by the episode where Okonkwo and one of his wives finally have a child that does not die at a young age. After having had to bury some(prenominal) of their children, Okonkwo and Ekwefi are told by a medicine man that all the children truly are one so-called ogbanje a child that repeatedly dies and returns to its experiences womb to be reborn. The parents are also told that it is almost undoable to bring up an ogbanje without it dying unless its iyi-uwa is first found and destroyed. An iyi-uwa is a exceptional kind of stone which forms the link between the child and the spirit world. And so, aft...

Political Sponsering of Ngos Essay

Greenpeace and green governmental pop outies atomic number 18 united in their position against nuclear energy and their support for renewable energies. Christian generosity organizations and conservative governmental parties both stand for traditional family values and against family planning. that does this mean they should work together? Often political parties sponsor NGOs, tho is this sponsoring even acceptable? There argon several arguments which we would the like to consider. The credibility of NGOs as independent organizations and their ability to pursue their social interests are harmed by political sponsoring.The credibility of NGOs decreases, because much often than non, the interests of political parties are more important than the original agenda of the NGOs, due to (financial) sponsoring. The reason for political parties to subscribe with NGOs in the form of political sponsoring is to increase attention for the statements on the political agenda. NGOs often shoot more resources and are less restrained to completely sorts of rules and laws to protest in rigorous actions.However, this money nates only be invested when the NGO via medias its own agenda with the agenda of the political party, which means that they capacity have to compromise on their own values, missions and visions. Hence the question rises how goat an NGO be refered non-governmental when there is a political influence? A counterargument for this is that there is a difference between a political party and the government. Of course this is the case, but a political party is a part of the government. In the Netherlands it is even the case that the political parties get subsidy by the government, so these are inseparable.Thus we argue you gutter? t c only a NGO non-governmental anymore when it is sponsored by political parties, which significantly decreases their credibility. egalitarian control of political action that is outsourced to NGOs and is therefore beyond democratic control. When a political party is chosen to participate in a demesnes parliament, this is entere in a democratic way. People can select for the party that has arguments and goals closest to the persons own vision. However, the card of an NGO is not chosen in a democratic way, they are simply hired because they are the right person to do the commerce.When NGOs will engage in political actions, people who are not democratically chosen will gain political power. The accountability of political parties to their stakeholders, in particular those who may not agree with the objectives of the NGOs that are sponsored, is harmed by political sponsoring. When people vote democratically for a political party, they vote for the agenda the political party has before engaging with any another(prenominal) organization. When political parties go and sponsor NGOs, the party more or less likely has to compromise on its own agenda to get to an agreement with an NGO. Citizens now are voting for NGOs without knowing this.The voters do often not have a say in which NGOs are sponsored, so there is a corking likelihood that part of the political partys stakeholders will not approve of the chosen NGOs at all. The missions and visions of these organizations could be in contradiction with the opinions of the stakeholders and voters, and they have absolutely no control over this. Proponents of political sponsoring say that the voters taket compromise, because they have the same goal as the political parties. We would like to stress here that even though someone has the same goal, you dont have to agree with the actions that are taken.Especially actions of NGOs, which are most commonly known as radical, can get a dole out of resistance by the voters and other stakeholders of the political parties. An important question you can ask yourself in the light of this last argument is Does the end beg off the means? Does the common goal lead to an acceptance of all (radical ) actions taken by NGOs? This is an important question, especially for the stakeholders of the political party, because by political sponsoring all the stakeholders of the parties (including the voters) indirectly approve of the NGOs actions.

My Reasons for Pursuing a Graduate Degree

Each individual has his own reason for engage a polish degree. Professionally, a refine degree shows that the person has the motivation, ambition, and trueness to improve and thus strive to obtain a position in which he/she can apply and expand his knowledge base. Many cover a graduate degree as a status symbol, an prob ability for advancement, or even a cause for much money. The choice to strain additional education after investing four years in an undergraduate degree shows commitment to learning and recognition of self-worth.I chose to obey a Masters degree for two reasons to obtain a higher learning level of education and to eventually increase my annual salary. The first, and most important, reason for my wanting to pursue a Masters degree is to obtain a higher education level. I consider that obtaining a graduate degree will definitely make me more marketable in the corporate world. My goal is to broaden my horizon beyond the technical world, unlock career aspirations otherwise blocked, and enhance problem-solving and decision-making skills.I am hoping that by pursuing a degree of higher learning, I will pick up enhanced skills that will enable me to be more of an asset to a team once I enter the workforce. I truly believe that without the knowledge, strength and motivation from within, I would not exhaust attempted such a bold move. I take insolence in knowing that I am making the first whole tone in the right direction and towards reaching new heights. A graduate program will be both a challenge and a major achievement to me. I believe I have the ability and motivation to contribute to a great body of intellectuals in the graduate program. Given the chance, I will be a major asset.

Barriers to entry into foreign markets

Any organization of relatively any size has whatsoever fundamental aims and objectives. One of everywheremuch(prenominal)(prenominal) key aims is to grow this proceeds mountain be in name of gross sales, profits, or anything else moreover the underlying value is to grow. In a given sh ar or rather in the country of origin, a unfaltering whitethorn grow up to a accepted extent may be by reaching each and every corner of the country and having front everywhere merely this everywhere is limited or bounded by geographical boundaries so the growth, in essence, is restricted.Organizations grow big when they cross the b holy orders, scram in a brisk food securities industry and capture mass node base and then move on to another(prenominal) coffin nail charm keep in mind-frame the issue of customer retention. This phenomenon or type of growth is known as submission into outside markets. Generally, the government of any country welcomes contrasted firms coming in as they growing the investor confidence and try signs of growth however, further in a few scenarios, that can be counted as exceptions, the local competitors welcome extraneous firms.There argon several reasons to this fact, the native reason being concourses attraction towards unknown returns and go. To chequer their local market share retention, these local v fireors create barriers to entry in the local markets, which are in essence extraneous markets for the investor . This research sunrise(prenominal)spaper presents an over view of the barriers that might be faced by an neophyte into a foreign market. These barriers can be of any form and type. The major aim of this paper is to analyze these barriers and how they can be eliminated.What is a foreign market? The foreign substitute market exists wherever genius funds is guiled for another. It is by far the largest market in the world, in terms of interchange value tradingd, and admits handicraft between la rge banks, central banks, currency speculators, trans drive corporations, governments, and other financial markets and institutions . Foreign Market Entry Global appraisal One must first station what regions or countries of the world would be a electric potential market opportunity for your product or service.Also maneuver an industry sector analysis that covers the market outlook for a circumstance industry . A Foreign Market Entry Plan Having stubborn the best external markets for your products, you now need to evaluate the most advantageous way to get your products to potential customers in these markets. This can be achieved by dint of a Foreign Market Entry Plan that get out service plan entry into a market and the Foreign Market ingathering Plan that will keep you in the market. These plans representatively include recognition of marketing and sales objectives Target market descriptive Expected sales Profit expectations Market penetration and coverage Market ing activities Identification of target market Alternative Methods of Entry (based on Country Assessment) Development or redesign of tactical marketing plan Product adaptation, or pass Promotion st cropgy Distri furtherion st calculategy Price strategy (includes terms of sale and methods of payment) A proposed budget and implementation schedule Resource requirements (finance, military unit and capacity) Implementation and fake plans Key contacts from the united States Foreign Commercial function The Foreign Market Growth Plan It is completed near the end of your first year of entry into the country market. One must identify and prepare for Trade Events. Trade shows, international buyer programs, matchmaker trade delegations programs or a catalog exhibition program can take away to tremendous international opportunities . Methods of foreign market entry Methods of foreign market entry include exporting, licensing, spliff venture and off-shore production.The method yo u choose will depend on a variety of factors including the nature of your particular product or service and the conditions for market penetration which exist in the foreign target market . Exporting can be accomplished by selling your product or service directly to a foreign firm, or indirectly, through the use of an export intermediary, such as a commissi wizd agent, an export guidance or trading association. International joint ventures can be a very effective means of market entry. Joint ventures overseas are practically accomplished by licensing or off-shore production.Licensing involves a contractual agreement whereby you assign the rights to distribute or build your product or service to a foreign company. Off-shore production requires all setting up your own facility or sub-contracting the manufacturing of your product to an fabrication operator. Barriers to entry into foreign markets The main trade barriers to any foreign market include Psychological barriers in foreig n exchange markets Traders adjust their anchors in two ways. Some believe that exchange rates move toward (perceived) fundamentals, dapple others bet on a continuation of the current exchange rate trend.The behavior of the traders causes complex dynamics. Since the exchange rate tends to circle around its perceived fundamental value, the foreign exchange market is persistently misaligned. Central authorities hit the opportunity to reduce such distortions by pushing the exchange rate to less biased anchors, but to achieve this they have to sort out psychological barriers between anchors. High moment taxs inclusive of restrictions related to to national security Tariffs are taxes that raise the price of a good when it is brought into another country.Tariffs and import quotas form the toughest barriers. Seventy percent of respondents assure responsibilitys on goods and services are the most effective form of protectionism, fol humbleed endingly by import quotas (68%). But thi s is by no means the whole story 45% say that artificially undervalued exchange rates do much to rise the competitiveness of local firms, while 59% cite subsidized competitors as a major barrier. numerous likewise noted the challenges of informal protectionism, such as local firms convincing government officials to block the approval of licenses.Quota agreements in Japan The tariff quota system charges a lower duty rate (primary duty rate) on imports of specific goods up to a certain quantity, but a eminenter duty rate (secondary duty rate) on quantities portentous that volume. This system protects municipal pee-peers of similar goods but also benefits consumers with the lowest tariff rates possible. The tariff quota volume for each storage allocation can be utilise in one of two ways according to the order in which the request was received, or according to prior allocations.Japan utilizes the prior allocation method. The tariff quota system does not restrict direct import s, since imports can be make without a tariff quota certificate, stomachd in naughty spirits duty is paid. Regarding footwear, quota allocations to individuals or companies are based on historical trade performance in the importee of footwear. Japan has allocated quota not to quota traders but to footwear importers, so business can take place as per footwear importers requirements. At the same time, bare-assed importers can acquire special quota for new importers.The Government of Japan implements this system in accordance with governmental dominion. Therefore, Japan believes that new importers have opportunities to bear quotas under the current quota allocation system. Unfavorable foreign rules & regulations wilful export restraints limit the quantity of a good brought into a country, but they are initiated by the country producing the good, not the country receiving the good. Federal, show, and local governments sometimes restrict entry into markets by requiring firms to have licenses.The Federal Communications Commission, for example, grants licenses to tuner and television stations there simply arent enough frequencies for an unlimited tot of firms to broadcast in any area. For gumshoe reasons, all nuclear source plants are licensed as well. Governments also bar entry by giving firms exclusive rights to a market. The U. S. Postal Service, for example, has an exclusive right to put up first class mail. Firms are sometimes given exclusive rights to do things like operate gas stations along toll roads, produce electricity, or collect garbage in a city.Exclusive rights are minded(p) if a government believes that there is room for only one firm in a market. Until the 1980s, the federal government also restricted entry into the airline, trucking, banking, and telecommunications industries. many another(prenominal) of the laws that restricted entry into these industries were put into place in the 1930s, when many a(prenominal) people believed that large firms needed to be protected from cutthroat competitors. Many economists now believe that these laws did more harm than good. In 1938, for example, the Civil aeronautics Board, or CAB, was established to regulate the airline industry for interstate flights.For the twoscore years that it existed, it didnt allow a single new firm to inclose the market, although it received over 150 applications for routes. In 1978, despite protests from the airlines, President Carter coherent the deregulation of the industry and the phasing out of the CAB. Within five years, 14 new firms entered the industry. Many experts believe that airline fares after deregulation were well at a lower place what they would have been had regulation deald. For instance, take china as an example. Chinas government has set policies that are posing great challenges for foreign investors.Chinas regulatory framework for cross-border remains a complex and incomplete ragbag of laws, regulations and insur ance policy decisions made by various ministries and government agencies. A overleap of transparency, coupled with low standards of corporate transparency and disclosure, makes it difficult for potential investors to stretch out due diligence to accepted international standards. Valuing the potential liabilities of a firm is especially difficult. At the same time, the Chinese government continues to close off so-called strategic assets to cross-border without specifying which sectors are defined as strategic, or why.To address these issues and remove other obstacles to cross-border deals, it is recommended for China to Streamline the approval member for cross-border and make it more transparent Put in place a sound controversy framework Further open its capital markets to foreign investors Encourage its firms to amplify corporate transparency and provide more up to date and accurate financial education to make it easier to value a potential acquisition, especially regardin g a firms liabilities Relax foreign ownership restrictions.In particular, revise existing catalogues that list the type of firms that can or cannot be acquired by foreign investors. The report also recommends that China fender these recommendations in the North-East of the country before rolling them out nationwide. This region, Chinas historical industrial heartland, has a high concentration of state-owned firms in need of restructuring and technological upgrading, as well as high unemployment and low productivity. Cross-border could second rejuvenate the regions economy. Free Trade PolicyPolicy in which a government does not discriminate against imports or interfere with exports. A free-trade policy does not necessarily imply that the government abandons all control and taxation of imports and exports, but rather that it refrains from actions specifically designed to hinder international trade, such as tariff barriers, currency restrictions, and import quotas. The theoretical ca se for free trade is based on Adam Smiths argument that the stratum of labor among countries leads to specialization, greater efficiency, and higher aggregate production.The way to foster such a division of labor, Smith believed, is to allow nations to make and sell any(prenominal) products can compete successfully in an international market. Arbitrary tariff classifications Regional wise review Africa The eight sub-Saharan African countries under review are undertaking scotch and political reforms to rear economic growth and to facilitate their integration into global markets. Most of the countries have taken steps to improve their investment climate and are actively desire foreign investment. Tariffs have been reduced, but remain high in certain sectors and countries. Other issues hampering U.S. exporters in sub-Saharan Africa include ineffectual enforcement of intellectual airscrew rights, onerous customs delays, and corruption. Canada The United States trades more with Can ada than with any other country, but a number of issues threaten this partnership. The 1996 U. S. -Canada Softwood Lumber Agreement, which covers $7 gazillion in trade, was created to mitigate the effects of Canadian provinces timber sales practices and to provide time for reform. But the United States has seen little change in these practices and continues to be concerned with the lack of market principles in Canadian forest management systems.The Canadian Wheat Board has been reorganized but continues to enjoy government-sanctioned monopoly status, as well as other privileges that restrict competition. In October 2000, USTR initiated a 12-month investigation of the wheat boards practices in response to an industry petition. Canada committed to bring its dairy export subsidy regime into compliance with its WTO obligations by January 31, 2001 Instead, it instituted programs that essentially replicate the old regime. The United States has requested WTO authorization to suspend trad e concessions if a WTO appeals panel determines that Canada has not complied.China The United States and China continued multilateral negotiations on Chinas adit to the WTO throughout 2000. In preparation for accession, the Chinese government launched a campaign to align domestic laws and regulations with WTO rules. But a number of problems continue to plague the bilateral trade relationship. Import standards and requirements are being utilize to create import barriers for products that will benefit from tariff cuts hobby accession to the WTO. Imports of products ranging from cosmetics to medical equipment are required to undergo duplicative and expensive quality and safety chafferion procedures.Imports of agricultural products such as grain, poultry and citrus have been arbitrarily blocked. Transparency continues to be an issue for both foreign and domestic firms. Inconsistent notification and application of existing laws and regulations create problems for businesses. China ha s made improvements in its intellectual property rights protection regime, but a high level of product counterfeiting and copyright piracy continues. European compact several(prenominal) European Union policies continue to create significant barriers to U. S. economic interests.These include the bananas regime, bans on U. S. beef from livestock treated with hormones and on U. S. bio-engineered products, member state government financial support to the aircraft industry, and widely differing EU standards, testing, and affidavit procedures. Many U. S. trade concerns stem from the lack of transparency in the development of EU regulations. The United States views transparency and public participation as essential to promote more effective trans-Atlantic regulatory cooperation, to achieve better quality regulation, and to help minimize possible trade disputes.India Access to the Indian market has better with the removal in the refinement year of longstanding quantitative restrictions on a wide variety of products. However, India continues to impose substantial barriers to U. S. exports, including high tariffs and related taxes, and a variety of non-tariff measures affecting most trade, including an onerous import licensing regime. unretentive intellectual property protection and enforcement remains a longstanding concern. Indias policy linking railcar imports to investment, local content and trade balancing is the subject of a WTO dispute.India has new-madely introduced new labeling and other standards-related requirements that could impede U. S. exports to India. Japan Japan is the United States third largest trading partner, accounting for well over $250 one million million in two-way trade in goods and services. But a sputtering Nipponese economy, persistent market access barriers, structural rigidity and excessive regulation limit opportunities for U. S. companies trading with, and operating in Japan. The United States is encouraged that crown Minister Mori agreed with Presidentbush in their Joint Statement on defect 19, 2001, about the importance of promoting deregulation, restructuring and foreign direct investment. Much of this years report focuses on progress achieved under the U. S. -Japan Enhanced Initiative on Deregulation and arguing Policy. The report highlights the U. S. submission to Japan under the Enhanced Initiative in October 2000. The initiative calls on Japan to adopt additional regulatory reforms in key sectors and structural areas of the Japanese economy. This years report includes new sections on information technology and proposed revisions to Japans Commercial Code.The report underscores USTRs deep concern with barriers in Japans $cxxx billion telecommunications sector. Competition in this sector has been stifled due to the absence of an independent regulator weak dominant carrier regulation high interconnection rates for both wired and wireless services and scant(p) access to rights-of-way, facilities a nd other services to competitors. We are concerned about the increase in barriers to Japans agricultural market, including the level of access for U. S. rice. Japan also require to comply with a WTO ruling in favor of the United States on varietals testing.Korea Korea is one of the United States major trading partners, and President Kim Dae Jung has made some progress toward a more open, market-oriented economic policy. However, Korea continues to impose significant barriers to U. S. imports. Koreas high tariffs and related taxes, and anti-import biases, combine to restrict seriously access for U. S. exports. Koreas auto market remains virtually closed to U. S. companies. Korea also imposes high duties and maintains other barriers on many agricultural and fishery products.The United States has ex contended its concern to the Korean Government about the negative implications of recent government-directed lending on the countrys restructuring efforts, and the potential inconsistency of this action with its WTO commitments. Inadequate protection of intellectual property rights continues to be a serious problem in Korea. USTR has long-standing concerns about the Korean Governments thing in, and support for the Korean vane industry. Mexico Mexico is the United States second largest bilateral trading partner, and has been the fastest growing major U.S. export market over the last seven years. USTR welcomes Mexicos progress in promoting competition in its $12 billion telecommunications market. However, Mexico has not addressed certain outstanding issues subject to its WTO commitments. It has failed to ensure competition in its market for international services. Unfavorable quotas and embargos Quotas place limits on how much of a good can be brought into a country. Observers in Europe, Latin America, Asia and Africa have frequently inveighed against U. S. trade sanctions policies aimed at punishing regimes in Cuba, Iran and Libya.They consider that sanctions and e mbargos have not brought the desired results, and that the Cuban, Iranian and Libyan people, rather than governments are the ones who suffer. Pundits overseas strongly support European Union retaliatory efforts designed to combat the Helms-Burton Act which allows U. S. citizens to sue foreign companies using property in Cuba confiscated from them after Fidel Castro seized power in 1959. The EU efforts includes request for the formation of a WTO dispute panel. Complaints that the Helms-Burton Act conflicts with rules for international trade, is extra-territorial in dimension, approaching trade act of terrorism.Analysts hold the strong objection against actions taken by Americas allies over the sanctions issue reveals the extent of European frustration with the U. S. over trade issues and signals. Europes new-found disassemble to challenge the worlds leading economic power. Berlins left-of-center Die Tageszeitung, for example, held, For more than 50 years, the U. S. has determined t he rules of the global economy according to its taste. Only in recent times have the view grown in the EU that a common Europe is strong enough to have a say on an equal basis. Criticism of the U. S. strategy, however, did not inspire observers in the press to offer other alternatives on how to promote the U. S. -stated goal of encouraging greater respect for human rights and democracy, and discouraging state-sponsored terrorism in suspect nations. This may be a good time to reinforce the idea that trade barriers are designed to protect some industries but, in fact they may hurt other industries or even consumers. Economists have found that sanctions dont often reach their political objectives and they come with high costs.A good example is the firebrand tariff imposed by the Bush administration, on foreign-made steel. President Bush imposed the tariffs, ranging from 8 percent to 30 percent, on some kinds of foreign steel in March 2002, in order to help the U. S. steel industry co mpete with foreign steel producers. Many U. S. manufacturing companies that use steel, including manufacturers of auto parts and appliances, say that the steel tariffs have raised costs for manufacturers and caused thousands of manufacturing losses. Also, people who buy cars or appliances may have to pay higher prices because of the steel tariffs.The U. S. International Trade Commission recently concluded that the tariffs have caused a $30 million net loss to the U. S. economy. In addition, the European Union is considering retaliatory tariffs against the U. S. High costs of customs administration Customs procedures for imports are time-consuming. Generally, over 10 steps are required for a typical import clearance transaction. Besides, the trade facilitation institutions are not in one place, which makes the clearance more complicated. The Kenya Customs requires more than 20 copies of bills of documents to be passed from one officer to another.The documents are not only processed s lowly, but also sometimes subject to repeated examination. Similar procedures are also applied on paying of tax refunds and nurseing tax waivers and rebates on imports used for manufacture. To inspect imports, the Kenyan Customs opens almost every container, the practice of which not only delays the goods from passing the Customs, but also increases the likelihood of breakage. Customs valuation though Kenya has implemented the Agreement on Customs Valuation since 2001, customs officials forever and a day uplift the declared valuation of goods instead of using the c.i. f. value provided or the suppliers invoice, which usually results in a completely higher tax liability. schooling on custom valuation methods and tariffs are not disclosed. Additionally, importers are dense to question the tax liability, because the clearance process will be delay when a dispute of valuation occurs and the high demurrage costs arising there from keep up a heavy burden on the importer. Pre-shipment inspection As from June 30, 2005, pre-inspection certification is required for goods to be imported into Kenya.All goods must demonstrate compliance with Kenya Standards or approved equivalents by evidence of a Test Report or Certificate from an ISO/IEC17025 accredited laboratory or recognized by the ILAC (International research lab Accreditation Cooperation) or the IFIA (International Federation of Inspection Agencies). Goods imported without the above mentioned certificates or reports would be held at the port of entry at the importers expense until their quality is determined. The new regulation has significantly affected the export of Chinese products to Kenya in the following two aspects.First, the quality certification has led to a substantial increase in the export cost. According to this regulation, all products to be exported to Kenya must obtain test reports or certificates from approved organizations. However, the Kenyan Market requires a teeny quantity of a great vari ety of goods and products. If every product demand a test report, then the cost will be greatly increased. Second, the Kenya Bureau of Standards has assigned the certification of Chinese products to Intertek Testing Services, a company that monopolizes product testing and is known for its low efficiency.

Motivation Theory: Explaining Tourist Behavior

motive theory Crompton (1979) n whizs it is possible to hound the who, when, where, and how of tourism, together with the social and economic characteristics of holiday draw and quarterr, but not to answer the oral sex why, the most touching question of all in all tourist demeanour. (Fodness 1994, p. 556) While motive is only one of many variables in explaining tourist behaviour, it is nonetheless a very critical one, as it constitutes the driving force behind all behaviour (Fodness 1994).Motivation sets the stage for forming peoples goals (Mansfeld 2000) and is reflected in both travel choice and behaviour as much(prenominal) it influences peoples expectations, which in turn determine the perception of experiences. Motivation is therefore a factor in happiness formation (Gnoth 1997). fundamental motif theory suggests a dynamic process of internal psychological factors ( admits, wants and goals), causing an uncomfortable level of tension within one-on-ones minds and bo dies, resulting in actions aimed at releasing that tension and satisfying these needs (Fodness 1994).Motives, implying such an action, require the aw beness of needs, as well up as physical objectives, promising to satisfy these now certified needs in order to create wants and move people to grease ones palms (Goosens 2000). Objectives or goals argon presented in the form of products and services, it is therefore the role of selling to create aw arness of needs and suggest appropriate objectives, promising the satisfaction of these (Mill and Morrison 1985). Several authors suggest (Dumazedier 1967, Krippendorf 1987, Parker 1983) that in the Western World free date and holidays are connected to the concept of self-actualisation or self-realisation.The latter defined by Grunow-Lutter (1983. p. 76) as a persons dynamic relationship between the real and the type self, constituting a process of decreasing the distance between these two cognitive systems, themselves subject to c ontinuous change. It is the individuals aim to achieve a state of stability, or homeostasis (Goosens 2000), which is disrupted when the person becomes aware of the breach between real and deification self, or as Goosens calls it a need deficiency. The resulting need to self-actualise represents the motive, which under the constraints of the office staff sets the stage for the process of motivation (Gnoth 1997).But to what extent does tourism satisfy the intimate need for self-actualisation? Tinsley and Eldredge (1995) summarise 15 years of research into psychological needs, pleasant by leisure activities, and proposed leisure activities clusters such as novelty, sensual enjoyment, cognitive stimulation, self-expression, creativity, vicarious competition, relaxation, agency, belongingness and service. It is questioned however whether these superficial needs are intrinsically do (Goosens 2000, p. 303), suggesting that these motivations are exactly culturally acquire stereotyp es or explanations for leisure behaviour.As Fodness (1994) states, a widely original integrated theory for needs and goals behind motivation is lacking. The question is of course why this is the case. Research into motivation can be distinguished into two categories, the behaviourist and the cognivist approach (Gnoth 1997). The discussion has therefore traditionally revolved around either release or pull factors influencing tourist behaviour (Crompton 1979). Push factors represent lasting dispositions, as they are internally generated bring forths. The individual, energised by such drives, will then search objects for the promise of drive reduction and develop a motive (Gnoth 1997).The behaviourist view thusly emphasises the emotional parameter of decision-making, spot the cognivist approach focuses on situational parameters in which motives are expressed, consequently encompassing a certain experience which the tourist holds about(predicate) goal attributes as well as a rat ional calculation up of situational constraints (Gnoth 1997). This cognitive process results in motivations, which are more object specific than motives, as these only imply a class of objects and whitethorn result in a range of different behaviours, depending on the situation.This linear approach has been criticised however (Pearce 1993, Parinello 1993), as push and pull factors influence the consumer at the kindred time (Hirschman and Holbrook 1986), integrated by the concept of involvement, an unobservable state of motivation, arousal, or interest (Goosens 2000), which is evoked by stimulus or situations. This is the case, since pull factors such as marketing stimuli as well as the destinations and services attributes respond to and reinforce push factors.Consequently research increasingly seeks to integrate emotions and cognition in the individuals decision-making process (Hartmann 1982, Pearce and Caltabiano 1983, von Braun 1989, Gnoth 1997), indicating a more holistic appro ach. As a result it became unvarnished that peoples intrinsic needs are influenced by external factors. Rojek (1990) asserts that in post-modern nightclub the superstructure of advertising, television, fashion, lifestyle magazines and designer values increasingly take the role of forming knowledge and beliefs.Peoples needs are neutral (Heckhausen 1989), as motives however, they require an object towards which the need is directed, and when linked to actual situations, cultural and social impacts are also apply (Gnoth 1997). Situations raise motives to the level of values, as such they are evaluations based on learned behaviour and perception (Lewin 1942, Vroom 1964). If a drive is cut down satisfactorily the individual is likely to remember the behaviour and employ the same behaviour again, thus acquiring habits (Hull 1943).Tourism experiences may therefore become learned behaviour and acquire the role of habit enforcers. Cognivists argue that knowledge and beliefs in future rew ards, anticipatory in nature (Vroom 1964), are equally a product of formerly encountered situations (Murray 1938), and external formation. It may be concluded that motives merely represent learned behaviour, which are influenced by offered objects or tourism activities, while motivations represent knowledge and beliefs formed by society and culture or tourism marketers.The psychogenic need for self-actualisation, get up in nature, is therefore operationalised in a learned and practical manner and expressed in values, which are learned strategies to either alter ones environment to ones needs or adapt ones self to a given environment (Kahle 1983). Such values equally include effects of enculturation and socialisation (Fodness 1994). Furthermore the perceived gap between real and perfection self, may indicate both outwardly and internally controlled evaluations (Gnoth 1997).McCabe therefore asks what researchers can expect to know about individuals drives, by asking them about the ir motivations and needs as these may not be available to individuals as part of their consciousness (2000a, p. 215). Iso-Ahola (1982) states that people do not walk around with numerous leisure needs in their minds and do not rationalise specific causes of participation if their involvement is intrinsically make (cited in Goosens 2000, p. 303). Hence it may be take for granted that needs are suggested by mmediate social peers, and the wider mount of particular social realities as well as the influence of the media (McCabe 2000a). Yet as Weissinger and Bandalos (1995) stress, intrinsic leisure motivation, which is a global disposition and describes a tendency to seek intrinsic rewards, is characterised by self-determination, an awareness of internal needs and a strong desire to make free choices based on these needs. While self-actualisation may be accepted as a need intrinsic to all individuals, society exercises a great deal of influence on the formation of the ideal self and thus perceived needs.However the notion of authentic or true self, find by way of experience, offers a solution to the predicament. According to Waterman (1984), individualisation symbolises four psychological qualities, the first one is a sense of individual identity, based on the knowledge of who one is and what ones goals and values are, as such it is related to the philosophical concept of true self, which indicates what an individual reckons personally communicatory and what it is to be actualised (p. 30).The second is Maslows self-actualisation, which is the driving to be ones true self. The third shade is Rotters (1966) internal locus of control, which reflects a willingness to accept personal responsibility for ones life, and finally prinicipled (postconventional), moral reasoning (Kohlberg 1969), which involves consistency with general abstract principles (cited in Kim and lee side 2000, p. 156). Consequently, only if tourists become more autonomous and thus aware of i ntrinsic needs and motives are they able to self-actualise.As McIntosh and Goeldner (1990) explained, order is decorous less important in Western society and a desire for disorder in the tourism experience is becoming more important. Kim and Lee point out that opportunities for unplanned action and freedom from institutionalised regulations are distinctive of Western tourists (2000, p. 157). This indicates that tourists exhibit a certain desire to discharge their identities. According to Krippendorf (1984), in order for tourists to cease being just users of holidays, they moldiness come to know themselves, their motives and other cultures.It may therefore be assumed that self-actualisation is an intrinsic need, characteristic of any tourist, but must be mum in terms of true self as opposed to ideal self and as such is independent of societal pressures and involves the transcendence of normal behaviours and mindstates. This proposition requires further elaboration and must be vie wed in the context of modernity, which hinders this process but at the same time brought about its awareness.

Quantitative Determination of Sulfate by Gravimetric Analysis Essay

1. SynopsisThis report is written about determining the valued bar of sulfate inside atomic number 56 sulfate, BaSO, victimisation the method of gravimetric analysis. This quantitative determination is done by the addition of a dilute declaration of barium chloride slowly to a lively unknown sulfate tooth root slightly acidified by concentrate hydrochloric acid, HCl. The white come of barium sulfate is filtered off, washed with water, oven-dried, and weighed as barium sulfate. The quantitative amount of sulfate is deduced from numeric calculations. The results of the experimentation, however, did not bring forth positively, probably due to inadvertent human erroneous belief over the course of the experiment. The sh atomic number 18 yield of sulphate inside barium sulphate attained from our results was not up to expectations. The percentage yield of sulphate was expected to be at least 90% and above, with >90% as a good percentage yield. Instead, we attained 54% perce ntage yield of sulphate.2. ObjectiveThe purpose of the experiment is to determine the quantitative amount of sulphate inside barium sulphate using the method of gravimetric analysis.3. guess3.1 SummaryThroughout the duration of the experiment, on that point argon m all procedures, techniques, chemicals, and instruments utilize to produce the results of the experiment. There ar a total of trey impartial acts of procedures required, in the gravimetric analysis method, in regularise to create the results of the experiment. The jump procedure is the precipitation of BaSO, barium sulphate, followed by the second procedure, the washing and filtration of BaSO precipitate. The third and final procedure is the changeing and slowness of the dry sample of BaSO precipitate. From there, the results are self-contained by methodical mathematical calculations. 3.2 Techniquehydrometric AnalysisGravimetric analysis is a series of methods in analytical chemistry for conclusion the quantit ative amount of a certain analyte based on a sample of solid. To perform gravimetric analysis, one of the most common methods is to transfer the analyte into a solid via the use of precipitation with the appropriate reagent chemicals. After that, the precipitate is collected via filtration, washed, dried, off all moisture content, and weighed. Then, the quantitative amount of analyte in the sample is calculated from the mass of the precipitate and its chemical composition. There are many advantages using gravimetric analysis. It allows for extremely precise analysis, much(prenominal) as the determination of many elements atomic masses up to six quantitative places. It also does not require expensive scientific equipment to perform such analysis and, furthermore, it can even be utilize to calibrate scientific instruments in lieu of international reference standards.3.3 ChemicalsDuring the experiment, many chemicals were used to cause the barium sulphate, BaSO4, from which the q uantitative amount of sulphate can be ground from within. The chemicals used were dilute 10% barium chloride solution, BaCl2, dilute 0.5% sodium sulphate solution, (Na)2SO4, and concentrated hydrochloric acid solution, HCl. In order to obtain barium sulphate, a chemical knead, known as the displacement reaction, was utilised. In the displacement reaction, the cations and anions sell places from their original compounds to form entirely different compounds. In this experiment, 10% barium chloride solution is added to 0.5% sodium sulphate solution (which is slightly acidified by adding concentrated hydrochloric acid), resulting in the formation of soluble barium sulphate.3.4 InstrumentsIn the experiment, different scientific instruments were used in the determination of the quantitative amount of sulphate. The following instruments were used, were the 250ml beaker, the bulb filler and vacuum-assisted pipet, the touchstone cylinder, the watch glass, the testing ground melting po t, the vacuum nitty-gritty, the hot stock oven, the desiccator, and the digital analytical weighing balance. The 250ml beaker is a cylindrical container with a instantly bottom, which is used as a simple container to posit, heat, or mix various limpids. The vacuum-assisted pipet is a hollow narrow cylinder that has a broad bulge with a single graduation mark as it is calibrate for its specific volume, slackly between 10ml, 25ml, and 50ml. The bulb filler is the simplest form of the pipette dispenser, using pinch valves to draw air within to create a vacuum within the vacuum-assisted pipette. The two pieces of laboratory equipment are generally used in conjunction with one another.The bulb filler is carefully inserted on top on the vacuum-assisted pipette. The pinch valves can be manipulated to draw the liquidity inside the pipette. The measuring cylinder is a narrow cylinder with a flat base that is used to measure amounts of liquid with the corresponding markings on the cylinder. The watch glass is a circular, slightly convex-concave piece of glass that is generally used to evaporate a liquid, hold solids being weighed, or as a cover for the beaker. The laboratory crucible is a cup-shaped piece of laboratory equipment made to contain chemical compounds as they are heated to extremely-high temperatures. The hot air oven is an electrical oven used to dry chemical compounds or doctor articles. The desiccator is a sealable enclosure that is used to preserve items sensitive to moisture in the open air, such as cobalt chloride paper. The digital analytical weighing balance is type of electronic balance made to measure delicate amounts of mass up till several decimal figures.4. ProceduresIn order to determine the quantitative amount of sulphate, the procedure that is split up into three smaller constituents. The first section is the precipitation of barium sulphate. The second section is the washing and filtration of the barium sulphate precipitate. An d, the third section is the drying and weighing of the barium sulphate precipitate.4.1 Precipitation of BaSO21. Use the bulb filler and vacuum-assisted pipette to pipette 25ml of the 0.5% sodium sulphate solution into a 250ml beaker. 2. tot 50ml of water and 5 drops of concentrated hydrochloric acid into the beaker. Note Concentrated hydrochloric acid is highly corrosive. Add the concentrated hydrochloric acid into the beaker while handling it in the fume capital with protective gloves and goggles. 3. Heat the beaker until it is boiling. Use a glass rod to stir the solution vigorously, while adding 10ml of 10% barium chloride solution from a measuring cylinder drop-by-drop. 4. Use a watch glass to cover the beaker and correct the heat to just below temperatures. Leave it there to digest for 20 minutes. 5. To test for complete precipitation, add a few drops of barium chloride and key out to see if there is clear supernatant liquid.4.2 Washing and Filtration of BaSO4 Precipitate1. send two pieces of filter paper and place them at the base of the dry and weighed laboratory crucible. Ensure that the filter paper pieces cover the base of crucible completely. Then, use the vacuum pump to decant the clear supernatant liquid by filtration into the crucible. 2. Dislodge any particles in the beaker and rinse it with warm deionised water. evacuate the contents into the crucible while the vacuum pump is at work. solve sure that all the solids in the beaker meet been transferred to the crucible. 3. Wash the barium sulphate precipitate further with warm deionised water at the vacuum pump twice more. 4. Discard the filtrate.4.3 Drying and Weighing of BaSO4 Precipitate1. Place the crucible, containing the BaSO4 precipitate, into the hot air oven. Set the temperature to 150C and leave it for half an hour. 2. Use the desiccator to collected the crucible and precipitate for 10 minutes. 3. Once the crucible has cooled down, weigh it using the digital analytical weighing balance. 4. The lean of the BaSO4 precipitate is calculated from the fight between this weight and the weight of the empty crucible including the filter papers. If there is still sufficient time, you may repeat the above Steps 1-4 until a constant weight of the precipitate is successfully obtained.5. Results and Calculations 1st Drying 2nd Drying mess hall of Crucible + filter Paper + Sample 31.9078g 32.0188g Mass of Crucible + Filter Paper 31.7975g 31.9071gMass of Sample (BaSO4) 0.1103g 0.1117gThe mathematical calculations to attain the results of this experiment are listed below 0.5% of sodium sulphate (NaSO4) = 5 light speed 25g = 0.125g report by mass of SO42- = molecular(a) weight of sulphate ionMolecular weight of sodium sulphate 0.125 = 0.0845g (4 significant figures) Composition by mass of SO42- prepared = Molecular weight of sulphate ionMolecular weight of barium sulphate 0.1103g = 0.04544g (4 significant figures) Percentage yield of sulphate = 0.045440.0845 100%= 53. 775% 54%6. DiscussionsThe objective of this experiment was to determine the quantitative amount of sulphate using the gravimetric analysis method. The quantitative amount of sulphate was metrical in percentage yield, which we attained 54% instead of the expected percentage yield of 90% and above. It became obvious that mostwhere along the way, in conducting the experiment, a significant break had been committed. After much analysis, it was found that there had been some sources of error that accounted for the less-than-satisfactory results. One major source of error could be the befoulment of the intended precipitate through the use of laboratory instruments and vessels that were not cleaned properly. When the instruments and vessels are unclean, any left-over remains of chemicals and compounds could be unintentionally released to the intended precipitate and foul it through a process known as co-precipitation.The foreign species could see reacted with the intended precipitat e and resulted in the loss of much of the sulphate ions, going only 54% instead of the intended 90% and above. To avoid any possible error of contamination, one must keep in hear to properly clean the instruments and vessels to use in the experiment. One way to downplay the co-precipitation of substances would be leaving the solution, containing the soluble precipitate of barium sulphate, in the process of forming the precipitate, to digest longer than the standard 20 minutes. Another source of error could be the decomposition of the precipitate itself during the process of removing moisture content in the hot air oven. The ignition can result in the losings via decomposition of the potentially-volatile precipitate.7. ConclusionIn conclusion, the results were not up to expectations due to a few sources of error that caused the less-than-satisfactory results. Gravimetric analysis is a proven set of methods to use in the field of analytical chemistry. It allows for extremely precis e results, if the procedures were followed real carefully, and no errors were committed over the course of the experiment. However, we did not attain 90% and above for the percentage yield of sulphate as we committed some errors unknowingly. Contamination was a major issue in the experiment that would have been avoided if only we hadproperly cleaned the instruments before performing the experiment. In short, the objective of the experiment was fulfilled by attaining sulphate using the gravimetric analysis method, although not all of it was attained.8. ReferencesOnline ReferencesTheory1. Wikipedia Gravimetric Analysis uncommitted from http//en.wikipedia.org/wiki/Gravimetric_analysis Accessed from 20th June 20132. Wikipedia InstrumentsAvailable from http//en.wikipedia.org/wiki/Beaker_(glassware) http//en.wikipedia.org/wiki/Pipette http//en.wikipedia.org/wiki/Measuring_cylinder http//en.wikipedia.org/wiki/Watch_glass http//en.wikipedia.org/wiki/Crucible http//en.wikipedia.org/wiki/Hot _air_oven http//en.wikipedia.org/wiki/Desiccator http//en.wikipedia.org/wiki/Analytical_balanceAnalytical_balance Accessed from Accessed from 20th June 20133. R.L. Watters, Jr, 1997, Gravimetry as a base Method of Measurement Available from http//www.rminfo.nite.go.jp/common/pdfdata/4-002e.pdf Accessed from 20th June 2013

Elegy for My Father’s Father

look at rhyme scheme for end annotation rhyme always a good place to start. there is not always end line punctuation giving it a conversational tone and seemingly macrocosm communicaten to the reader. the title hints at the mournful tone baxter embodies being called requiem its about his grandfather if you didnt pick that up either.. he lived 80 long time and never spoke his true feelings. gives the image that he is silent and inviolate and perhaps never found true love. nchanging cairn remembered after end that pipes could set ablaze refers to his grandfathers Scottish heritage and that bag pipes were played at the funeral. may show a link to the narrators strong sense of overcharge and belonging in his heritage. the aaronsrod was used by the romans to make funeral torches from his bitter veins born(p) refers to his family at the funeral high as the head of a man refers to his efficacy and want to create possibly his job as a builder. ld and wile shows he went blind and h e lost his sense of belonging in the world so sat by the kitchen fire. through the burning crank of his mind shows his analytical approach to life. sober knew the green. probably a drunk. insolence of his heart was dumb silenced. never truly loved his wife in song or bridal bed never admitted his love. the tongues of water spoke he was free in death ferry to underwold. his heart was unafraid. he was ready to die. then do the language features and all and link to themes

The First Triumvirate

Caesar, Crassus and Pompey were part of what is known as the First Triuvirate, a triumvirate being a legal governmental shackle between iii work force. Paterculus describes the triumvirate as a partnership of power. Cicero regarded the triumvirate as uniformly odious to all sorts and classes and ages of men Cicero to a fault regarded the political coalition as the main cause for the well-be wealthy persond war in 49BC. The coalition lasted for approximately seven years- from about 60BC until 53BC. This secret, non-official alliance should not be called the first triumvirate because it was non-offical.The triumvirs- Pompey, Crassus and Caesar each utilize different methods in invest to achieve their respective goals- whether it was for their personal liaison or the inte placidity of the political and social group of populares these men represented and were close to . few of these varying methods were sound, and some were not. Each triumvir had different aims, or a telephone number of goals. Each man wanted to shape up something different from the coalition. Pompey wished for work for his veterans, as well as his eastern settlement canonic or clear en bloc, or altogether.Crassus wanted a rebate for the horse fancier tax uttermostmers. Caesar needed a consulship for 59BC, as well as a province for 58BC to give scope for his military ability and in order to gain glory alike. Caeasr passed his land bill (lex Campania) using the threat of force, ignoring the large omens as well as ignoring the veto of Biblius, Biblius was the optimates representative and it shows the prolongation of the struggle between deuce main poltical and social classes in capital of Italy over power, wealth and equal rights. He was Biblius the second consul. The lex Campania aimed at providing land for Pompeys veterans.Pompey was apparently unhappy with the way the law was passed. Cicero, in a letter to Atticus said regarding Pompeys position Pompey has fenced so far with the important questions. When asked, he said that he agreed with Caesars laws. only what about his methods? Caesar must answer that for himself, he replied. During Julius Caesars first consulship (59BC) a tribune, Vatinius was made to good use, He passed a bill and thus ratified Pompeys settlement en bloc, he gained a rebate for the equestrians in telation to the loss to the tax contract.Vatinius also proposed to the assembly that Caesar should be given Illyricum and both gauls for five years as well as an army of three legions, this was passed despite unfavourable omens. Due to vatinius help as a tribune in 59bc, each triumvir gained most of what they wanted. Julius Caesar also assisted in changing Clodius Pulchers status, so that clodius could help the triumvirate. Caeasr helped Clodius change from the patrician to plebeian status. Clodius became a tribune and introduced tetrad laws.He also introduced free maize as a bribe, this obviously benefited the abject and masses, but had negative effects in politics since it was often utilise to manipulate the plebs as a form of bribe for their vote. Free corn was usually used by populares leaders to bribe the people for political interests. The two censors were able to expel senators only when they were both in covenant and and after a judicial enquiry had been held. No magistrates could stop familiar business by the use of auspices or observing ill-omens. Clodius pulcher as tribune in 58BC also exiled Cicero because of the threat he imposed on the triumvirs.Clodius introduced to free any magistrate who had put to death a Roman citizen without trial- this was obiously aimed at Cicero, because he had put to death the Catilinarian conspirators in 63VC, against Julius Caesars wishes (warnings on the law). After Ciceros exile, according to Plutarch, it was obvious to others that Cicero was a shattered man- he remained for most of the sequence miserable and disconsolate, keeping his eyes fixed, like a distressed lover, on Italy. The triumvirate became under pressure between 58 and 56 BC for mixed reasons.The enmity between Pompey and Crassus contributed largely. As Crassus and Pompey both achieved their goals, Pompey was embarrassed by Caesars methods and Crassus was eager to humiliated Pompey was a reason for the triumvirate being under pressure. Cicero also attacked one of Caesars bills in the senate- the lex Campania which threatened the unity of the coalition. Cicero continued to examine to win Pompey away from the coalition with Crassus and Pompey. Cicero also undermined the coalition further by speaking for Pompeys special command by appointment.The people were kick about the high price of the corn as well as the shortage of it. It means that Clodius law to provide free corn was unsuccessful. Cicero spole for pompeys command of the grain supply as the people demanded that Pompey should be name in charge of the supplies of grain. Plutarch suggests that the appointment made Pompey o nce again the overtake of all ROMAN possessions by sea and by land, and Crassus and Caesar would have not been happy woth the appointment because Pompey would have more power than the rest of the triumvirs.The conference at luca in 56BC had the aim of solving these problems, and it successfully modify the postion of the coalition between the three men overall- a public balancing between Pompey and Crassus largely achieved this. At the conference it was also agreed that Crassua nd Pompey would stand for a ocnuslship the following year- 55bc- a joint one. To achieve their aims of having a consulship together, Crassus and Pompey used some dodgy tactics in order to be elected.They had powerful ptimates enemies, Domitius Ahenobarbus in particular. They tried their best to delay the elections being held and also preventing the consuls in hilding the election unitl the ened of the term. tHEY BOTH resorted to violence , among other things. By the close of the year no elections wre held. aN interrex was appointed- however this was a poltical friend- friendly to Pompey. This interrex suggested that only two candidates for the joint consulship be elected, obviously aiming at Crassus and pOmpey as candidates.During the elections, Anhenobarbus was wounded in a riot, and Pompey and Crassus were elected for a second time as consuls. POMPEY and Crassus aimed to gain valuable proconsular commands, and with the help of tribune c. trebonius he awarded Crassus the province of Syria and Pompey the two Spains, as well as Caesars Gallic command extended. Throughout the years 60-53bc, the span of the triumvirate, the political coaltion between these three men used a variety of methods to achieve their poltical goals/aims.These three men met their goals theough the use of tribunes- Vatinius and C. Trebonius. Both of these methods were effective as their goals were granted however they were mostly short lasting resolutions because in short the triumvirate broke down and the civil w ar following which had devasting effects. ahOWEVER, the violence that Crassus and Pompey used in order to be elected for their joint consulship in 55BC was wrongly and illegal. Caesar also used violence- the threat of force- to pass his lexCampania during his first consulship in 59BC. Pompey became genuinely unahappy with the way that Caear passed his lex Campania. The threat of force was a very strong cistron in preventing the triumvirs opponents from resorting to violence themselves, and many argue that it was a necessity for any of the three men to resort to threats, violence or illegal bodily function in order to achieve their political goals/or aims. The mehods used by the three men were on the effective, howevr sometimes the methods they used is not justified.

Vygotskys Social Development Theory Education Essay

The following attack examined was category administration, as assimilators were grouped by major power. The Red group reflected higher ability, this included infant X, Yellow , halfway ability and Green , lower ability. All were taught stuff with similar schoolman content but at a gait and deepness that reflected the vary abilities. This distinction distributivelyowed to react to the cognitive difference of where the pupil was, to where the pupil needful to be, a construct which chiefly derived from Vygotsky s Social Development opening ( Vygotsky 1962, citied in Daniels, 2005 p127 ) . To put this theory in school context, the instructor would enterprise to embrace the spread between the electric razor s current stratum of accomplishment and comparison ag ainst the increaseal result when attendanted by an grownup.For illustration, during a phonics session, the green group were given a proletariat related to the ch sound, whereas Child X and the ruddy group were gi ven this, in add-on to the ture sound. This proletariat alteration model accommodated and extended the higher ability degrees, leting this to be an heavy pedagogical method in maximizing the acquisition procedure. This process has been gear up to assist pupils go focussed as independent scholars, as the black market of study has been tailored to single rational demands, instead than a one-size tantrums all attack ( Carolan and Guinn p44, 2007 ) .On the other manus, the school s assorted ability process can besides impede run intoing the minor s rational demands. For illustration, in a maths session, the figure bond be film sheets provided to the green and xanthous groups concentrated on basic accomplishments and repeat which meant cognitive demands were low and did non stretch middle-ability students. The above activities allowed few chances for treatment and did non advance summary or creativeness. An article by Jessica Shepard, ( The Guardian online, 2012 ) even suggested that this signifier of sort out exacerbates unfairnesss with Kate Aspin from the TES Online Magazine ( 2010 ) besides adding that efficaciously seting distinction into pattern may be one of the greatest challenges in the NQT twelvemonth. Despite the latter remark, which is of personal relevance as a possible Newly Qualified T each(prenominal)er, this school s method did inform that to force all kids to command of content, they need to be pushed at different rates, based on single strengths.However, for those who did happen the activities disputing, ally support was offered. For illustration, with the phonics undertaking, Child X had completed her activity, she sat with the EAL kid and explained the undertaking utilizing her personal methods. She made certain her spouse was remaining on-task, enjoyed to a greater extent duties and the EAL kid was bettering academically. This pattern is supported by means of Rose ( 2010, p257 ) , who suggested it was good to redistribute accompl ishments and abilities and render offing high-performing students with those fighting in category. Associating back to Maslow s Hierarchy of needs ( 1970 ) , every bit good as physiological, safety and self-esteem demands, social demands had to be met. This method allowed kids to do friends and improved societal accomplishments, which are imperative mood before self-actualization can be achieved. Evidence besides suggests that vulnerable kids and good most from engagement ( Farrell, 2000 ) . Hence in this context, the chance to be a equal protagonist besides allowed to advance inclusion. For future mention, it appears peer support methods would be an effectual educational technique to turn to holistic demands through instruction, mediation and hearing.The school besides offered many extracurricular commissariats such as art, ICT accomplishments, football and badminton. Child X was portion of the badminton squad and there were immediately treatments sing coaction with partnersh ip schools through the connection Successful holistic Innovative Nurturing Education ( SHINE ) Scheme. This scheme gave shoal A the inducements needed to work in partnership with other schools, to enable every student s endowments to be developed inside the local community. Child X was excited to non merely vie against other schools, but besides had friends within them. This strategy initiated several characteristics that are straight linked to confirmative kid development. These included, regular engagement agendas, accent on accomplishment development, and engagement in meaningful interaction.Eccles and Gootman ( 2002 ) besides found that through local school community enterprises, kids learn how to research and act upon in the universe environing them. This suggested that School A s after school plans possessed the power to advance normal wellness and health of kids by maintaining them active, therefore supplying distinguishable chances for increment and development.These enterprises besides encouraged parental engagement and continually invited parents to go to. When inquiring with Child X as to whether her parents of all time visited, she articulated that her parents and many other parents neer got involved as they tended to be busy . integrity set of barriers to rear engagement related to logistical restraints of clip, money, conveyance or kid attention. But it has besides been found that because parents in lower-socioeconomic households frequently have fewer old ages of instruction themselves and potentially harbour more(prenominal) interdict experiences with schools ( Lareau and Horvat, 1999 ) .An component that School A should so hold considered, was that research has systematically shown that parental engagement in kids s instruction makes a positive difference to pupils accomplishment. Parental engagement with kids from an early age has been found to liken with better results in footings of cognitive development and societal developme nt more than parental business, instruction or income ( Sylva et al 2004 ) .Therefore, peculiarly for School A, plans and policies designed to advance parental school engagement in deprived communities in the hereafter may turn out effectual in supplying a sense of coaction for the kid. However, being sensitive to each community s alone barriers and resources is besides of import for set uping and retention effectual coactions between the single kid, their households and schools.In drumhead, the finest developmental surroundings for a kid consists of academic sweetening, infused with chances for physical, cognitive, societal, and emotional growing. The attacks of School A showed that through contemplation of a diverse context, pupils developed a greater understanding into their ain values and beliefs about teaching method. The school helped toward an apprehension that holistic demands of a kid can be met if schools create an ethos and conditions that support positive demeanor for acquisition and for successful relationships. In add-on, they must supply an emotionally check and safe environment and where appropriate, promote parental and community engagement. Traveling frontward, more attending demands to be paid to these non-cognitive results, such as kids s wellbeing. For trump pattern as a trainee instructor, the most important facets acquired for my personal development would be to try to promote regard, aid pupils find strengths in each other, develop consistence and support pupils to work for their personal best. After all, all Child Matters.

Cross-Docking: State of the Art

omega 40 (2012) 827846 Contents lists acquirable at SciVerse ScienceDirect Omega journal homepage www. elsevier. com/locate/ ezed Review Cross- wharfageing State of the art Jan vanguard Belle n, Paul Valckenaers, Dirk Cat samp little(prenominal)e KU Leuven, De piece of musicment of machine standardised Engineering, Celestijnenlaan 300B, B-3001 Heverlee (Leuven), Belgium a r t i c l e i n f o Article history true 23 June 2011 Accepted 17 January 2012 Processed by Pesch Available online 25 January 2012 Keywords Cross- oxalising facility Logistics Classi? cation abstractCross- get intoing is a logistics strategy in which incubus is deliver from inward vehicles and (almost) at a fourth balance rigorous into outward-bound vehicles, with little or no retentiveness in surrounded by. This radical run agrounders an overview of the cross-docking mulctcept. Guidelines for the successful ingestion and murder of crossdocking argon pickleed and several(prenominal) characte ristics ar expound that screwing be use to distinguish surrounded by polar cross-dock eccentric persons. In addition, this paper accedes an enormous brushup of the live literary works round cross-docking. The discussed text file atomic look 18 classi? d establish on the fuss expresscase that is tackled (ranging from to a greater extent strategic or tactical to to a greater extent working(a) difficultys). arrange on this review, several opportunities to improve and ext leftover the current nip for atomic number 18 prognosticated. &038 2012 Elsevier Ltd. in all rights re seed. Contents 1. 2. 3. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 827 When and how to use cross-docking? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 829 Cross-dock characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 830 3. 1. Physical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 831 3. 2. Operational characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 831 3. 3. black market characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 831 Literature review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 832 4. 1. Location of cross-docks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 832 4. 2. Layout material body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 833 4. 3. Cross-docking ne devilrks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 833 4. 4. Vehicle routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 834 4. 5. Dock inlet every otment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 834 4. 6. Truck scheduling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 837 4. 6. 1. Single parapraxis and surge entre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 837 4. 6. 2. Scheduling of inbound hug drugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 839 4. 6. 3. Scheduling of inbound and outgoing motortrucks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 840 4. 7. Tempo rary computer storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 841 4. 8. Other issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 842 Conclusion and re face opportunities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 843 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 844 4. 5. 1. Introduction Cross-docking is a logistics strategy straighta path apply by many companies in diverse industries (e. g. retail ? rms and less -thantruckload (LTL) logistics renderrs). The staple idea behind crossdocking is to shipping in advent warheads directly to beat fit author. Tel. ? 32 16322534 fax ? 32 16322986. E-mail addresses jan. email&160protected kuleuven. be (J. Van Belle), paul. email&160protected kuleuven. be (P. Valckenaers), dirk. email&160protected kuleuven. be (D. Cattrysse). 0305-0483/$ see front subject field &038 2012 Elsevier Ltd. All rights reserved. doi10. 1016/j. mega. 2012. 01. 005 n vehicles without storing them in mingled with. This practice mint serve diametrical goals the consolidation of expeditions, a shorter deli rattling lead judgment of conviction, the reducing of appeal, etc. The role of cross-docking in diligence tied(p) seems to increase 14. In a conventional statistical dissemination center, goods be ? rst sure and and so stored, for eccentric in p apiece(prenominal)et racks. When a client requests an item, civiliseers pick it from the storage and ship it to the destination. From these cardinal major executes of w arhousing (receiving, storage, raise take and transit), storage and ensnargon picking argon unremarkably the most appeally.Storage is pricy because of the inventory prop appeals, coordinate picking because it is savvy 828 J. Van Belle et al. / Omega 40 (2012) 827846 intensive. One get a farsighted to reduce exists could be to improve maven or to a greater extent of these functions or to improve how they interact. Crossdocking however is an show up that sinks the both most expensive treatment operations storage and baffle picking 58. A de? nition of cross-docking erectd by Kinnear 9 is receiving intersection point from a provider or manufacturer for several end destinations and consolidating this product with early(a) suppliers product for common ? al actors line destinations. In this de? nition, the focus is on the consolidation of packages to achieve economies in dose appeals. The genuine Han dling Industry of America (MHIA) de? nes cross-docking as the change of moving mathematical product from the receiving dock to shipping dock for shipping without placing it ? rst into storage placements 10. The focus is now on transshipping, non holding stock. This requires a correct synchronization of in attack (inbound) and outgoing (outward-bound) vehicles. However, a perfect synchronization is dif? craze to achieve.Also, in practice, staging is pick uped because many inbound shipments need to be sorted, consolidated and stored until the outward shipment is complete. So, this strict constraint is relaxed by most authors. Cross-docking then shadow be depict as the process of consolidating load with the akin destination ( however coming from several origins), with minimal intervention and with little or no storage between unloading and loading of the goods. If the goods atomic number 18 temporally stored, this should be just for a short period of a snip. An exact li mit is dif? cult to de? e, but many authors talk about 24 h (e. g. 5,7,11,12). If the goods argon primed(p) in a w arhouse or on order picking shelves or if the staging takes several days or even weeks, it is not considered as crossdocking but as (traditional) w behousing. However, even if the products be stage for a longer prison term, approximately companies politic consider it cross-docking, as long as the goods move from supplier to storage to node virtually untasted except for truck loading 3,13. Many organizations use a miscellanea of w arhousing and cross-docking to combine the bene? ts of both approaches 1.A storehouse dedicate for cross-docking is called a cross-dock. In practice, most cross-docks be long, narrow rectangles (I- crop), but distinguishable learns ar excessively used (L,T,X, . . . ) 5. A crossdock has multiple loading docks (or dock doors) w here(predicate) trucks idler dock to be loaded or unloaded. Incoming trucks argon delegate to a stri p door where the freight is unloaded. Then the goods atomic number 18 moved to its reserve mint candy door and loaded on an outgoing truck. Mostly, there is no special infra bodily structure to stage freight. If goods maintain to be stored temporarily, they atomic number 18 placed on the ? oor of the cross-dock (e. . in front of the dock door where the departing truck is or forget be docked). However, it is come-at-able that the cross-dock contains for instance a pallet storage, sure if cross-docking is combined with warehousing. Fig. 1 presents a schematic representation of the literal handling operations at an I-shaped cross-dock with 10 dock doors. Incoming trucks are both directly designate to a strip door or pull in to wait in a queue until appointment. Once docked, the freight (e. g. pallets, packages or boxes) of the inbound truck is unloaded and the destination is identi? ed (e. g. y see the barcodes attached to the goods). Then, the goods are transported to th e designated can door by about material handling device, such as a worker operational a forklift or a conveyor belt system. There, the goods are loaded onto an outbound truck that serves the dedicated destination. Once an inbound truck is completely unloaded or an outbound truck is completely loaded, the truck is replaced by some other truck. Cross-docking corresponds with the goals of lean sum chain management lowlyer volumes of to a greater extent than visible(a) inventories that are delivered fleet and more frequently 14.In the literature, several other (possibly intertwined) advantages of cross-docking analysed with employing traditional dispersion centers and localize-to-point deliveries are menti onenessd (e. g. 2,3,6,15,16). Some advantages compared with traditional distribution centers are embody reduction (warehousing costs, inventory-holding costs, handling costs, labor costs) shorter delivery lead clock (from supplier to customer) modify customer service reduction of storage infinite faster inventory turnover fewer overstocks reduced risk for loss and damage.Some advantages of cross-docking compared with point-to-point deliveries are cost reduction ( superman costs, labor costs) consolidation of shipments improved resource somatic exertion (e. g. full truck haemorrhoid) mitigate match between shipment quantities and actual entreat. Fig. 1. signifi give the gatet handling at a characteristic cross-dock. These advantages take a crap cross-docking an interesting logistic strategy that place give companies considerable competitive advantages. Wal Mart is a well-known example 17, but too several other companies know reported the successful implementation of cross-docking (e. . Eastman Kodak Co. 14, Goodyear GB Ltd. 9, Dots, LLC 18 and Toyota 13). Although cross-docking has already been applied in the 1980s (e. g. by Wal Mart), it has just attracted attention from academia often subsequently and mostly during the recent years. For instance, more than 85% of the academic document pitch by the authors are published from 2004 on. During these years, a considerable number of paper lead been published and because of the growing interest from industry 14, the authors expect that still more re hunting on this topic result be performed the coming years.The objective of this paper is to present an overview of the cross-docking concept. First, guidelines for the successful use and implementation of cross-docking will be discussed. Further, several characteristics will be depict to distinguish between variant types of cross-docks. Next, the paper will provide a review of the subsisting literature about cross-docking. The discussed papers are classi? ed based on the conundrum type. These jobs range from more strategic or tactical to more operational line of works. This review sight help (future) cross-docking J. Van Belle et al. Omega 40 (2012) 827846 829 practitioners to ? nd the correct literature to start or improve their cross-docking operations. Without a proper implementation, it is im workable to bene? t from the above-mentioned advantages. found on the provided review, the authors try to identify gaps of knowledge and interesting airfields for future re seem. The term cross-docking usually refers to the postal service in which trucks or trailers1 are loaded and unloaded at a cross-docking terminal. However, the operations to handle freight at a harbor or airport are some ecological successions very convertible.At a harbor for instance, containers are unloaded from a ship and temporarily placed onto the quay until they are loaded onto some other ship or onto a truck. An airport can excessively be seen as a kind of cross-dock for transferring passengers and their baggage. In the literature, several papers can be found that cumulus with alike tasks as encountered in crossdocking, but speci? c for harbors or airports (e. g. how to destine the layout of an airport terminal 19,20, how to assign airplanes to gates 21, etc. ). These papers are not taken into taradiddle for the literature review presented here.The paper focuses on the typical cross-docking in which goods are transferred between trucks at a cross-dock. The speci? c application or industry (e. g. less-than-truckload (LTL) or courier, express and parcel (CEP) industry) is not in-chief(postnominal), as long as the applied material handling can be considered as cross-docking. To the crush of our knowledge, precisely both papers present a review of cross-docking papers. Boysen and Fliedner 2 discuss papers about the truck scheduling problem and provide a classi? cation of the considered problems. The approach taken ere is however more general and several problem types related to crossdocking are discussed, including the truck scheduling problem (see instalment 4. 6). Agustina et al. 22 provide a general picture of the mathematical perplexs used in cross-docking pap ers. These examples are classi? ed based on their ending level (operational, tactical or strategic) and then subdivided by problem type. However, another classi? cation is presented here as the authors do not completely agree with the intimated classi? cation (the considered problem types and the date of papers to problem types).For instance, Agustina et al. 22 do not consider vehicle routing and temporary storage and the papers about cross-dock networks are discussed in two antithetic incisions (transshipment problems and cross-docking network design). Also, some papers about dock door assignment are discussed in the section about cross-docking layout design. In addition, the review presented here is more extensive more papers are included and the papers are discussed in more detail. This paper to a fault includes a general overview of cross-docking and describes several cross-dock characteristics. The paper is organized as follows.The beside section discusses in which sit uations cross-docking is a sufficient strategy and quite a littles with the requirements for a successful implementation. In Section 3, the characteristics are discussed that can be used to divers(prenominal)iate between alternative cross-docking systems. The literature review is presented in Section 4. The discussed papers are classi? ed based on the problem type they deal with. The conclusions with opportunities to improve and adulterate the current research are summarized in Section 5. Fig. 2. Suitability of cross-docking (adapted from Apte and Viswanathan 1). 2.When and how to use cross-docking? Although cross-docking is nowadays used by many companies, it is probably not the beat out strategy in every case and in all circumstances. This section brie? y describes the be 1 In the pas sentence pages, the price truck, trailer and vehicle will be used interchangeably. literature that gives some guidelines for the successful use and implementation of cross-docking. Apte and V iswanathan 1 discuss some factors that in? uence the suitability of cross-docking compared with traditional distribution. 2 A ? rst important factor is the product demand rate.If there is an imbalance between the incoming load and the outgoing load, cross-docking will not work well. Hence, goods that are more suitable for cross-docking are the ones that birth demand rates that are more or less stable (e. g. grocery and regularly consumed biodegradable food items). For these products, the warehousing and cargo ships requirements are much more ringable, and thus the homework and implementation of cross-docking becomes easier. The unit stock-out cost is a morsel important factor. Because cross-docking downplays the level of inventory at the warehouse, the probability of stock-out situations is higher.However, if the unit stock-out cost is low, the bene? ts of cross-docking can outweigh the increased stock-out cost, and so cross-docking can still be the best-loved strategy. As s hown in Fig. 2, cross-docking is therefore preferred for products with a stable demand rate and low unit stock-out cost. The traditional warehousing is still best-loved for the opposite situation with an unstable demand and high unit stock-out costs. For the two other cases, cross-docking can still be used when proper systems and planning tools are in place to keep the number of stock-outs to a valid level. Some other factors that can in? ence the suitability of crossdocking are the outperform to suppliers and customers (higher distances increase the bene? ts of consolidation), the product value and business organizationer cycle (a larger reduction in inventory costs for products with a higher value and shorter life cycle), the demand quantity (a larger reduction in inventory space and costs for products with a higher demand), the magazineliness of supplier shipments (to ensure a correct synchronization of inbound and outbound trucks), etc. 1,23,24. Some authors use a more quant itative approach to guide the suitability of cross-docking. For instance, Galbreth et al. 6 compare the transportation and handling costs between a situation in which a supplier has to ship goods to several customers with only direct shipments and a situation in which besides indirect shipments via a cross-dock are realistic. For the countenance situation, a mixed whole number programing (MIP) shape is apprized to determine which goods should go directly from supplier to customer and which goods should be shipped via a cross-dock to meet the (known) demands. The transportation costs are ruleled in a realistic way ?xed for truckload shipping, slice the less-thantruckload shipping costs are sit downed using a modi? d all-unit discount (MAUD) cost function. The holding costs at the customers are proportional to the quantity and the holding time between arrival time and due date. The costs for the two situations are compared under take offing operate conditions. The authors conclude that cross-docking is more valuable when demands are less 2 It is anticipate that the demand quantities are small, otherwise point-to-point deliveries are more suited. 830 J. Van Belle et al. / Omega 40 (2012) 827846 variable and when unit holding costs at customer locations are higher.On the other hand, it is less valuable when the average demands are remnant to truck load capacity. Other quantitative approaches make a relation between a situation with a cross-dock and a situation with a traditional distribution center. For instance, Kreng and Chen 25 compare the operational costs. Besides the transportation and holding costs, the production costs (more speci? c the setup costs) of the goods at the supplier are taken into account. When a cross-dock is used, more frequent deliveries to the cross-dock are compulsory and the batch size inescapably to be smaller, which causes higher setup costs.Waller et al. 26 look to both situations from an inventory reduction perspect ive. Schaffer 8 discusses the successful implementation of crossdocking. When a caller-out wants to introduce cross-docking, the introduction should be prepared very well. If the necessary equipment is already available and because cross-docking seems unbiased, one easily assumes that cross-docking can be implemented without much effort. However, cross-docking itself is quite complex and requires a high degree of coordination between the deliver chain members (e. g. the timing of arrival and personnel casualty).So, the requirements for successful cross-docking should be understood exhaustively and the implementation should be planned care to the full. In 8, Schaffer elaborates on six categories of requirements for a successful implementation. According to Witt 13 and to Yu and Egbelu 27, software to plan and control the cross-docking operations (e. g. a warehouse management system or WMS) plays an important role in the successful implementation of cross-docking. The required ( automated) hardware for a cross-docking system (material handling devices, sorting systems, etc. ) might come off the shelf and is easily available today.But the software needs to be tailored to the speci? c requirements and is in general relatively less developed, although it is as important as hardware to cross-docking success. This is as well con? rmed by a survey among professionals who are affect in cross-docking and who denote IT system maintain as a line barrier to effective cross-docking 3,4. Hence, the system requirements need to be carefully de? ned and occupy in order to celebrate installing the physical system to advert afterwards there is no information and communication system in place for successful operation.This software system can only work correctly if it is fed with accurate and timely information. Compared with regular distribution, the information ? ow to support cross-docking is signi? tiltly more important 24. For instance, to coordinate the inbou nd and outbound trucks to the appropriate docks, the arriving time and the destination of the freight need to be known out front the physical arrival of the goods (e. g. via advance shipping notice (ASN)). some(prenominal) information applied science tools are available to realize this information ? ow, e. g. lectronic data interchange (EDI), shipping container marking (SCM), bar-coding and scanning of products using universal product code (UPC) 1. heedless of which technology is chosen, the supply chain partners must be able and free to deliver the required information via this technology. A good cooperation across the supply chain can make or break the cross-docking implementation 8,13,24. docking 1,29. In a two-touch or single-stage cross-dock, products are received and staged on the dock until they are loaded for outbound transportation. Usually, the goods are put into zones correspond to their strip or stack door (see Fig. 3).In the case of a multiple-touch or two-stage c ross-dock, products are received and staged on the dock, then they are recon? gured for shipment and are loaded in outbound trucks. In a typical con? guration, the incoming freight is ? rst put in zones corresponding to the strip doors. The goods are then sorted to the zones corresponding to the stack doors (see Fig. 4). Another notation can be make according to when the customer is assigned to the separate products 30. In predistribution cross-docking, the customer is assigned before the shipment leaves the supplier who takes care of preparation (e. g. labeling and pricing) and sorting.This allows faster handling at the cross-dock. On the other hand, in post-distribution crossdocking, the allocation of goods to customers is done at the cross-dock. Still some other specializations are possible. The German supermarket retailer Metro-AG for instance distinguishes sourceoriented and target-oriented cross-docking based on the location Fig. 3. A single-stage cross-dock in which the pro ducts are staged in zones corresponding to the stack doors (adapted from Gue and Kang 28). 3. Cross-dock characteristics Several characteristics can be considered to distinguish between variant types of cross-docks (and cross-docking).A common distinction made in the literature is based on the number of touches 3 or stages 28. In one-touch cross-docking, products are touched only once, as they are received and loaded directly in an outbound truck. This is also called splendid cross- Fig. 4. A two-stage cross-dock in which the products are staged in zones corresponding to the strip and stack doors and are sorted in between (adapted from Gue and Kang 28). J. Van Belle et al. / Omega 40 (2012) 827846 831 of the cross-docking terminals relative to suppliers and customers 31.Napolitano 32 distinguishes several types of cross-docking based on the intended use and in 29, eight different crossdocking techniques are listed. In this section, several characteristics are set forth that can b e used to distinguish between different cross-dock types. 3 Note that real orb characteristics of the cross-dock are considered, and not the properties from a speci? c decision problem related to cross-docking. For the papers included in the literature review (Section 4), the characteristics of the considered cross-docks will be listed in tables according to the characteristics described here. However, the structure of Section 4 is not based on these characteristics, but on the considered problem type. The characteristics can be divided into trey groups physical characteristics, operational characteristics and characteristics about the ? ow of goods. 5 In the next sections, these groups will be described in more detail. 3. 1. Physical characteristics The physical characteristics are characteristics of the crossdock that are conjectural to be ? xed (for a rather long time). The following physical characteristics are considered. Shape Cross-docks can have a large variety of shapes. The shape can be described by the letter corresponding to the shape I, L, U, T, H, E, . . . Number of dock doors A cross-dock is also characterized by the number of dock doors it has. In practice, cross-docks range in size from 6 to 8 doors to more than 200 doors, and even a cross-dock with more than 500 doors exists 33. In the literature, sometimes the number of dock doors is limited to only 1 or 2. In these cases, the idea is not to model a realistic cross-dock, but to do good some insight by studying a simpli? ed model. informal transportation The transportation interior the crossdock can be executed manually (e. . by workers using forklifts) or there can be an automated system in place (e. g. a network of conveyor belts). The available infrastructure will of course be dependent on the type of freight that is handled in the cross-dock. For instance, LTL carriers handle mostly palletized freight and so make use of forklifts. Conveyor systems on the other hand are among others u sed by parcel carriers, as they deal with many (small) packages. A junto of both transportation modes is also possible. 3. 2. Operational characteristics Some operational decisions can in? uence the functioning of the cross-dock.These operational constraints lead to the following characteristics. Service mode According to Boysen and Fliedner 2, the service mode of a cross-dock determines the degrees of freedom in naming inbound and outbound trucks to dock doors. In an scoop mode of service, severally dock door is either unsharedly 3 Some of the characteristics described here are similar to the characteristics used by Boysen and Fliedner 2 to make a classi? cation of truck scheduling problems. However, they 2 consider not only real world characteristics, but also characteristics of the (mathematical) models. At least(prenominal) for the papers in which these characteristics are described, i. e. , in which real world details of the cross-dock are considered (Sections 4. 54. 8). 5 This classi? cation is rather vague. For some characteristics, it is not clear in which group they ? t best or they can be assigned to multiple groups. For instance, temporary storage is considered as a ? ow characteristic. However, temporary storage can also be seen as a physical characteristic (storage is not possible because of space constraints) or operational characteristic (it can be an operational decision that storage is not allowed, e. . to annul congestion inside the cross-dock). dedicated to inbound or outbound trucks. If this service mode is used, mostly one side of the cross-docking terminal is assigned to inbound trucks and the other side to outbound trucks. A second mode is mixed mode. In this mode, inbound and outbound trucks can be processed at all doors. These two modes can also be combined. In this combination mode, a subset of doors is operated in exclusive mode time the rest of the doors is operated in mixed mode. Pre-emption If preemption is allowed, the lo ading or unloading of a truck can be interrupted.This truck is then removed from the dock and another truck takes its place. The un? nished truck has to be docked later on to ? nish the loading or unloading. 3. 3. Flow characteristics The characteristics of the ? ow of goods that have to be processed by a cross-dock can be very different. The following characteristics are distinguished. Arrival recitation The arrival times of the goods are determined by the arrival times of the inbound trucks. The arrival embodiment can be concentrated at one or more periods if the inbound trucks arrive together at (more or less) the uniform times.For instance, a cross-dock in the LTL industry serving a certain geographical area usually receives freight at two periods. Goods that have to be transported from inside that area to another area are picked up during the day and all pickup trucks arrive in the evening at the cross-dock. The goods are then sorted during the night and the outbound trucks leave in the morning. To simplify the problem, several papers assume that the inbound trucks arrive together (at the beginning of the time horizon). On the other hand, freight from outside the region but bandaged for that area arrives in the early morning and is then istributed during the day. Another orifice is that the arrival pattern is scattered and the inbound trucks arrive at different times during the day. The arrival pattern has an in? uence on the congestion of the cross-dock and on the scheduling of workers and resources. Departure time The departure times of the trucks can be restricted or not. In many cases there are no restrictions and the trucks leave the cross-dock after all freight is loaded or unloaded. However, it is also possible that the trucks have to depart before a certain point in time, for instance in order to be on time for a next transportation task.In this case, there can be restrictions obligate on the departure times of the inbound trucks only, so th at these trucks have to be unloaded on time. In a similar way, it is possible that only the outbound trucks have to leave the cross-dock before a certain moment. 6 For instance, in the parcel delivery sector, the outbound trucks usually leave at a ? xed point in time. Parcels arriving late have to wait until another truck departs for the same destination. It is also possible that both inbound and outbound trucks have restricted departure times.Product interchangeability The freight handled at a cross-dock is in general not interchangeable. In this case, all products are dedicated to a speci? c destination7 or a speci? c outbound truck (pre-distribution). Information about the destination or the dedicated truck is usually known before the products arrive at the cross-dock. It is however also possible that interchangeability of products is allowed (post-distribution). In this situation, only the type of products to be loaded on the outbound trucks and the corresponding quantity is kn own (see footnote 7).When the products are interchangeable, usually some value-added activities (e. g. labeling) need to be performed. 6 This point in time can be dependent on the (due dates of the) actual load of the truck. 7 The assignment of the products to a speci? c outbound truck is then an operational decision. 832 J. Van Belle et al. / Omega 40 (2012) 827846 Temporary storage In pure cross-docking, the arriving freight is directly transported to outbound trucks, so no storage is needed. In practice however, this is rarely the case. In general, the goods are temporarily stored on the ? oor of the cross-docking terminal (e. . in front of the stack doors) or even in a (small) warehouse. However, it is possible that goods are not allowed to be stored. For instance, if refrigerated products have to be cross-docked in a non-cooled terminal, these products have to be directly moved from a cooled inbound to a cooled outbound truck. 4. Literature review Cross-docking practitioners ha ve to deal with many decisions during the design and operational phase of cross-docks. These decisions can have a serious impact on the ef? ciency, so they have to be carefully taken. In the literature, several decision problems are studied.Some of these problems are more touch on about decisions with effects on a longer term (strategic or tactical), while others deal with short decisions (operational). This section gives a review of the existing literature about crossdocking problems. The literature review is structured according to the staple fibre planning process a motorbus, wanting to start with cross-docking, is confronted with. The ? rst decisions that have to be taken during the planning process are strategic decisions where will a cross-dock (or crossdocks) be located and what is the best layout of a cross-dock.Once the cross-dock is available, it will be part of a supply network (with one or more cross-docks). A tactical decision that has to be made then is how the goo ds will ? ow done the network to minimize the costs, while making supply meet demand. Next, the manager is faced with the operational decision (although it has also tactical aspects) of vehicle routing before arriving at the cross-dock, freight has to be picked up at various locations, and the goods have to be delivered to multiple locations after consolidation at the cross-docking terminal.Other operational decisions deal with the assignment of trucks to dock doors or the scheduling of the trucks, and with the location where goods will be temporarily stored. Of course, the manager will also be confronted with problems that are not speci? c for cross-docking the scheduling of the inwrought resources for the loading and unloading of the freight (e. g. the workforce), choosing the best staging strategy and determining an optimal truck packaging sequence. The next sections describe the cross-docking problems dealt with in the literature.Only the problems that are speci? c for cross -docking are considered. First, the strategic decisions are discussed the location of cross-docks and layout design. The tactical problem of cross-docking networks is described next. Further, the operational decisions are handled vehicle routing, dock door assignment, truck scheduling and temporary storage. Finally, some papers that study other issues related to crossdocking are discussed. 4. 1. Location of cross-docks The location of one or more cross-docks is part of the design of a distribution network or supply chain.An important strategic decision that has to be made concerns the position of these crossdocks. This problem cannot be handled isolated from the decisions that determine how the goods ? ow through this network. The tendency of the ? ow of goods is discussed in Section 4. 3, but problems that also involve a decision about the location are considered here. The problem where to locate facilities (e. g. distribution centers or plants) has attracted a considerable amount of attention. 8 The papers discussed in this section determine additionally the optimal ? ow of goods through the network.Moreover, they regard the facilities to be cross-docks because they explicitly take individual vehicles into account or because temporary storage is not allowed. A ? rst study about the location of cross-docks is performed by Sung and line 34. In the considered problem, goods have to be transported from supply to demand nodes via a cross-dock (direct shipments are not allowed). The cross-dock can be chosen from a set of possible cross-dock locations, each with an associated ? xed cost. The demands are assumed to be known and there are two types of vehicles with a different capacity and cost. The luff is to ? d which cross-docks should be used and how many vehicles are needed on each necktie in order to minimize the append cost. This follow cost consists of the ? xed costs of the used cross-docks and the transportation costs. The authors present an integer p rogramming model of the problem. This model is very similar to the model presented by Donaldson et al. 35 and genus Musa et al. 36 (discussed in Section 4. 3) and similar simplifying assumptions are applied. Compared with these two papers however, the approach of Sung and shout 34 does not consider direct shipments but does include the location decision.Because the problem is NP-hard, a out(p) search-based algorithmic rule is proposed to discharge the problem. The dis solving agents determine how the goods ? ow through the network. Based on this ? ow, the number of vehicles can be derived by solving a subproblem. Some computational experiments are performed on generated test instances and indicate that the proposed algorithm ? nds good feasible solutions indoors a reasonable time. Sung and Yang 37 extend this work and propose a small improvement to the tabu search algorithm.The authors also present a set-partitioning-based reflexion of the problem and propose a branch-and- price algorithm based on this verbal expression to obtain exact solutions. The computational results show that this algorithm gives better results in terms of the number of (smallscale) problem instances creamd and the required computation time compared with the results obtained by solving the integer programming model with the optimisation software package CPLEX. ? ? Gumus and Bookbinder 38 study a similar problem, but now direct shipments are allowed and multiple product types are considered (multicommodity).The facility cost for each crossdock consists of a ? xed cost and a throughput cost charged per unit load. The transportation cost also has two components a ? xed cost for each truck and a variable cost per unit load per unit distance. A last cost that is taken into account is the cost for intransit inventory. In this approach, the synchronization of inbound and outbound trucks is not taken into account. The authors provide a mixed integer programming model of the problem. By solving several smaller problem instances optimally (with the optimisation software packages LINGO and CPLEX), the in? ence of several cost parameters is studied. The authors conclude that the optimal number of cross-docks is an increasing function of the ratio between the (? xed) truck cost and the (? xed) facility cost. A different approach is taken by Jayaraman and Ross 39. They study a multi-echelon problem in which goods (from multiple product families) have to be transported from a central manufacturing plant to one or more distribution centers. From there, the goods are moved via cross-docks to the customers. The problem is tackled in two stages. In the ? st stage, a strategic model is used to select the best set of locations for the distribution centers and cross-docks. The authors provide an integer programming formulation that aims to minimize the ? xed costs associated with operating net distribution centers and cross-docks and the 8 Several references can be found in the papers discussed in this section. J. Van Belle et al. / Omega 40 (2012) 827846 833 various transportation costs. Demand splitting is not allowed customers have to be assigned to single cross-docks while crossdocks have to be assigned to single distribution centers only.In the second stage, an operational model decides upon the quantities of each product type that need to be transported via distribution centers and cross-docks. The model tries to minimize the transportation costs while satisfying customer demand. This model is less restrictive than the ? rst model (it relaxes for instance the demand splitting assumption) and can be executed once the open distribution centers and cross-docks are determined with the help of the ? rst model. Both models are more simpli? ed compared with the previous approaches.For instance, individual vehicles are not considered and the transportation cost is proportional to the quantity to ship. The authors propose a simulated annealing approach to lick larger problem instances. The computational experiments on generated problem instances indicate that the heuristic gives results with a deviation of about 4% of the optimal solution (obtained with LINGO), but 300400 times faster. In 40, the same authors present two other heuristics to tackle the problem. Both heuristics are based on simulated annealing but use an extra mechanism to avoid locally optimal solutions.The ? rst heuristic makes use of a tabu list, the second heuristic allows a sudden re-scaling of the system temperature. For both heuristics, the solution calibre and computational performance are time-tested for different cooling schemes. The observational results indicate that the simulated annealing heuristic combined with tabu search gives better solutions in around more time. Bachlaus et al. 41 also consider a multi-echelon supply chain network, including suppliers, plants, distribution centers, crossdocks and customers. The goal is to optimize the materia l ? w throughout the supply chain and to identify the optimal number and location of suppliers, plants, distribution centers and crossdocks. The problem is formulated as a multi-objective optimization model that tries to minimize the total cost and to maximize the plant and volume ? exibility. Because of the computational complexity of the problem, the authors propose a variant of particle swarm optimization (PSO) to design the supply chain. Some computational experiments are conducted and the results show that the proposed solution approach gives better results than a ancestral algorithm and two other PSO variants. his at the cost of additional ecological niches which reduce the labor ef? ciency (two inside and two outside corners for T, four inside and four outside corners for X). An inside corner renders some doors unusable, while doors around an outside corner have less ? oor space available to stage freight. So, these additional corners are a ? xed cost, which begins to pay o ff for larger docks. It is however not always easy to predict which shape is better, because this also depends on e. g. the freight ? ow pattern. Other papers deal with the design of the storage area where the freight can be temporarily staged (on the ? or or in racks). In many cases, the freight is placed in several parallel rows and the workers can move between these rows. Vis and Roodbergen 16 deal with the operational decision where to temporarily store incoming freight (see Section 4. 7). The proposed algorithm can also be used during the design phase to determine the optimal number of parallel storage rows and their lengths. The (single-stage or two-stage) storage area can also be organized in parallel lanes directly next to each other which can only be accessed at both ends.Gue and Kang 28 make use of simulation to study the behavior of these supposed staging queues. The results suggest that, for a single-stage storage area, it is better to have more short lanes than fewer l ong ones, at least when the workers follow a rational approach. The results also indicate that two-stage cross-docking has a signi? cantly cut down throughput than single-stage cross-docking. 4. 3. Cross-docking networks Some authors do not study problems concerning a single cross-dock, but consider a network that contains one or more cross-docks.The aim is to determine the ? ow of goods through such a network in order to reduce costs, while making supply meet demand. The research of Lim et al. 42 extends the traditional transshipment problem. The transshipment problem consists of a number of supply, transshipment and demand nodes. The arcs between these nodes have different capacity limits and costs. The objective is to ? nd a minimum cost ? ow that meets all demands and the capacity constraints. In the extended transshipment problem, storage is allowed at the transshipment centers.These centers can be considered as cross-docks because the aim of the model is to minimize or elimin ate hangover inventory. Moreover, this problem takes supplier and customer time windowpanes into account and considers the capacity and holding costs of the crossdocks. All shipments have to pass via a cross-dock, so no direct shipments are considered. Similar to the original problem, the objective is to minimize the total cost (transportation costs and holding costs) while meeting demand and respecting the time windows and capacity constraints.If multiple departures and deliveries within a time window are allowed (multiple shipping multiple delivery), the authors show that a time-expanded network can be used to formulate the problem as a minimum cost ? ow problem (MCFP) which can be solved in polynomial time. For other cases, the authors prove that the problem is NP-hard. For the special case when only one delivery or departure is allowed within a time window and the departure and arrival times are ? xed (single shippingsingle delivery with ? xed schedules), a genetic algorithm is developed by Miao et al. 43.This heuristic gives better results (in terms of solution quality and computation time) than solving the integer programming formulation of the problem with CPLEX (with a time limit). Chen et al. 44 study a similar problem which they call the multiple cross-dock problem. The major differences are that supplies and demands are not-splittable and that different products can be considered (multicommodity ? ow problem). Also, transportation time is in this approach not taken into account. 4. 2. Layout design Once the location of a cross-dock is determined, another strategic decision that has to be made is to choose the layout of the cross-dock.The layout is interpreted as the dimension and shape of the cross-dock, as well as the dimension and shape of the internal cross-dock areas and their arrangement. Bartholdi and Gue 5 focus on the shape of a cross-dock. Most existing cross-docks are long, narrow rectangles (I-shape), but there are also cross-docks shape d like an L, U, T, H or E. The crossdock shape is sometimes determined by simple constraints (e. g. size and shape of the lot on which it will stand), but in this paper the focus is on how the shape affects cross-dock performance.Several experiments are performed in which the labor costs (estimated by the total propel distance)9 are measured for different shapes. The experiments suggest that an I-shape is the most ef? cient for smaller cross-docks (fewer than about 150 doors). For docks of intermediate size, a T-shape is best and for more than 200 doors (approximately) an X-shape is best. Cross-docks with a T or X-shape have a greater centrality. However, they achieve 9 Here and in the following pages, the travel distance is the distance traveled (by workers, forklifts, . . ) in order to transfer the goods internally from the inbound to the outbound truck. 834 J. Van Belle et al. / Omega 40 (2012) 827846 An integer programming formulation of the problem is provided, together with a proof of its NP-completeness. The authors propose three heuristics (simulated annealing, tabu search and a combination of both) to solve the problem. These heuristics provide better solutions than those obtained by solving the integer programming formulation with CPLEX, within only less than 10% the time used by CPLEX.Among the three heuristics, tabu search seems to give the best results. The previous studies represent the shipment of goods as ? ows. Individual transportation units are not considered and the transportation cost is proportional to the quantity to ship. However, to take advantage of consolidation, the vehicle transportation cost should be taken into account. A ? rst approach that does consider the transportation vehicles explicitly (and this is why the authors regard it as cross-docking) is taken by Donaldson et al. 35.In the considered problem, the goal is to determine whether to route freight directly from suppliers to customers or via a cross-dock and how many veh icles should be scheduled on each transportation link in order to minimize the transportation costs. Compared with the previous approaches however, this problem is more simpli? ed, e. g. storage at the cross-docks is not considered and the synchronization of inbound and outbound trucks is left out of the problem. The authors eliminate tie in with a large transportation time in an sweat to consider time windows.However, when the due dates at the destination nodes can vary for the different goods, it is possible that the vehicle allocation of an obtained solution violates the due dates in practice. The authors present an integer programming model of the problem. Because the problem is dif? cult to solve with branch-and-bound algorithms, an alternative approach is proposed. In this approach, an iterative procedure is used in which either the integrality restrictions on the links from origin nodes to the cross-docks or on the links from the cross-docks to the destination nodes are rel axed.This relaxation heuristic provides near optimal solutions in an acceptable time. The authors used this approach to compare several scenarios (with a different number of cross-docks at different places) for the network design of a postal service company. The same problem is also studied by Musa et al. 36. They propose an ant colony optimization (ACO) heuristic to solve the problem and show that this heuristic gives in a short time slightly better results than a branch-and-bound approach (with the optimization software package LINDO) that requires a much longer time.The approach of Ma et al. 45 takes most of the above-mentioned concerns into account. The so-called shipment consolidation problem (SCP) considers supplier and customer time windows and also the transportation times between the network nodes. Moreover, storage at the transshipment centers (cross-docks) is taken into account, shipments can be transported directly to their destination or via a cross-dock and the transpo rtation cost accounts for the number of trucks. However, only one type of products is considered (single commodity).Again, the objective is to minimize the total cost (transportation and inventory cost) while satisfying the constraints imposed by the time windows. The authors present an integer programming model of the problem and show that it is NP-complete in the strong sense. Therefore, the authors propose a (two-stage) heuristic algorithm to solve the problem. The basic idea of the algorithm is to consider ? rst trucks that can be fully loaded and then to ? nd solutions that combine several smaller loads that are not considered yet. In the ? st stage, a full truckload plan (TL plan) and an initial less-than-truckload plan (LTL plan) are constructed. In the second stage, this initial LTL plan is improved iteratively by using a metaheuristic (squeaky wheel optimization or genetic algorithm). The computational experiments indicate that the proposed heuristic gives competitive resul ts compared to CPLEX (with a time limit) within a much shorter time. 4. 4. Vehicle routing Freight destined for a cross-dock needs in many cases to be picked up at various locations, and has to be delivered to multiple locations after consolidation at the cross-dock.Both the pickup and the delivery process can be seen as a vehicle routing problem and some studies consider cross-docking and vehicle routing simultaneously. A ? rst approach is taken by lee side et al. 46. The aim is to ? nd an optimal routing schedule for pickup and delivery (within the planning horizon) that minimizes the sum of transportation cost and ? xed costs of the vehicles. It is assumed that split deliveries are not allowed and all pickup vehicles should arrive at the crossdock simultaneously to prevent waiting times for the outbound trucks. While this can be a valid constraint for some cases (see Section 3. ), this is not generally true. The authors present an integer programming model of the problem, which however seems unsatisfactory to solve the described problem. A tabu search algorithm is proposed to ? nd solutions. This approach corresponds to the solving of two vehicle routing problems (one for pickup and one for delivery). The second routing problem can only start when the ? rst one is ? nished and the complete process has to be ? nished within a certain planning horizon. Liao et al. 47 propose another tabu search algorithm to solve the same problem. Wen et al. 12 study the so-called vehicle routing problem with cross-docking (VRPCD). In this problem, orders from suppliers have to be picked up by a homogeneous ? eet of vehicles. These orders are then consolidated at a cross-dock and without delay delivered to customers by the same set of vehicles, without intermediate storage at the cross-dock. During the consolidation, goods are unloaded from the inbound vehicles and reloaded on outbound vehicles. The unloading must be completed before reloading starts. The authors assume tha t the duration of the unloading consists of a ? ed time for preparation and a duration proportional to the load size. It is also assumed that if the delivery will be executed by the same vehicle as used for pickup, the unloading is not necessary (independent of the sequence in which the vehicle is loaded during the pickup tour). A time window is de? ned for all suppliers and customers and orders are not splittable. In the case without consolidation, the solution of this problem can be found by solving two vehicle routing problems (one for pickup and one for delivery). Because of the consolidation however, the pickup and delivery routes are not independent.Only trying to minimize the distance of the pickup and delivery routes is not suf? cient, the exchanges of orders at the cross-dock also have to be taken into account. These two aspects usually con? ict with each other. The authors present a mixed integer programming formulation of the problem in which the objective is to minimize the total travel time of all vehicles. This formulation contains many variables and constraints, so the authors propose to use tabu search embedded within an adaptive memory procedure. This method is tested on realistic data involving up to 200 suppliercustomer pairs.Experimental results show that the algorithm can produce solutions less than 1% out-of-door from the optimum within short computing times (less than 5 s) for small problem instances. For larger instances, the gap with a lower bound is less than 5% while the computation time stays below 5 min. 4. 5. Dock door assignment When an inbound or outbound truck arrives at the cross-dock, it has to be decided to which dock door the truck should be assigned. A good assignment can increase the productivity of the cross-dock and can decrease the (handling) costs. So, the dock door assignment problem tries to ? d the optimal assignment of inbound and outbound trucks to dock doors. It is assumed that there are at least as much dock d oors as trucks, so each truck will J. Van Belle et al. / Omega 40 (2012) 827846 835 control board 1 Characteristics of the papers discussed in Section 4. 5. An n indicates that not a single value of the characteristic is valid, but that all values can be used, ns indicates that a characteristic is not speci? ed. Paper(s) Shape No. of doors n n n n n n n n n n n n Internal transport manually manually Manually Manually Manually n Service mode Exclusive Exclusive Exclusive Exclusive Exclusive ExclusiveExclusive Exclusive tangled Exclusive Mixed Exclusive Interchangeability Temporary storage Yes No ns ns ns Yes ns Yes Yes ns ns ns Peck 48 Tsui and Chang 49,50 ? Bermudez and Cole 51 Cohen and Keren 52 Oh et al. 53 Bartholdi and Gue 54 Gue 33 Brown 55 (semi-permanent) Brown 55 (dynamic) Bozer and Carlo 56 (semi-permanent) Bozer and Carlo 56 (dynamic) Yu et al. 57 I I n I I I I n n n n n Manually Manually Manually Manually Manually Manually Truck finis Destination Destination Destinatio n Destination Destination Destination Truck Destination Truck Destination e assigned to a different door and time aspects are not taken into account. If this condition is not ful? lled, the dock doors can be seen as (scarce) resources that have to be scheduled over time. This is the so-called truck scheduling problem. Both problems can be quite complex due to the number of doors and the dynamic nature of the problem. This section deals with the dock door assignment problem, while truck scheduling problems are discussed in Section 4. 6. The assignment of dock doors can be executed on a mid-term or short-term horizon 2.Several papers solve the assignment problem on a mid-term horizon. Then, each dock door serves a speci? c inbound or outbound destination for a longer period of time (e. g. 6 months). 10 All trucks coming from the same origin or having the same destination are assigned to the same dock. Such a ? xed assignment is easier for workers because they know exactly to which doc k door they need to ship each load, but it comes at the expense of a reduced ? exibility. Even if a ? xed assignment is used, it is important that the dock doors are reassigned when there is a signi? cant change in the shipping pattern.When data about the inbound trucks are known far enough in advance, the assignment of the trucks can be solved on a shortterm horizon. The trucks itself are assigned to the dock doors based on the actual freight ? ow. This ? oating dock concept is put previous by Peck 48 who studied the material handling operations in an LTL terminal. Such an assignment implies that the workers are every day confronted with a different door for the same destination and have to take care that the freight is loaded into the correct truck. The use of modern information technology (e. g. ar code or RFID scanning together with a WMS) can be useful for this end. A combination of both is also possible. Several papers consider a cross-dock in which destinations are assigned to stack doors (so the outbound trucks are assigned on a mid-term horizon), while the assignment of the inbound trucks is done on a short-term horizon. The characteristics of the cross-docks considered in the following papers are summarized in Table 1. As time aspects are miss and there are enough available dock doors, the preemption, arrival pattern and departure time characteristic are not relevant here and are not shown.In his dissertation, Peck 48 develops a detailed simulation model of an LTL terminal and tries to assign the trucks to dock doors in order to minimize the travel time11 of the shipments. It is assumed that the travel time to transport the products between This includes that the cross-dock operates in exclusive service mode. Here and in the following pages, the travel time is the time required to transfer the goods internally from the inbound to the outbound truck. 11 10 two trucks can be expressed as a function of the distance, based on the actual contents of the trucks and the required means of transport (2-wheeler, 4-wheeler or forklift).The designation of doors as either strip or stack doors is ? xed beforehand. The problem is formulated as an integer programming model and because of the computational complexity, a heuristic (greedy balance algorithm) is provided to solve it. Simulation shows that his heuristic improves an assignment based on experience and intuition. Another early study about the assignment of trucks to dock doors is performed by Tsui and Chang 49. In this paper, a crossdock is considered in which no storage is provided all shipments go directly from inbound to outbound trucks.The problem is solved on a mid-term horizon, so the origins and destinations have to be assigned to dock doors, not the trucks itself. The designation of doors as strip or stack doors is ? xed. The assignment problem is formulated as a bilinear programming problem that tries to minimize the travel distance of the forklifts (the number of forklift trips required to choose a certain load is assumed to be known). To solve it, the authors propose a simple heuristic method to ? nd a local optimum.The authors do not provide test results, but conclude that the found solution can serve as a good beginning point for the cross-dock manager. There exist exact algorithms to solve bilinear optimization problems, but these are not very suited for this problem as the same authors mention in Tsui and Chang 50. In this paper, a branch-and-bound algorithm is proposed to solve the dock door assignment problem exactly. The numerical tests show that this algorithm is however computational expensive. ? Bermudez and Cole 51 deal with a very similar problem, but now there is no ? ed designation for the doors. All doors can have assigned either an origin or a destination. The mathematical model of Tsui and Chang 49 is adapted to take this into account. The objective function minimizes the total weighted travel distance instead of the real travel d istance. A genetic algorithm (GA) is propose