Research Paper代寫范例-選址決策對企業(yè)成功的影響。本文是一篇本站提供的research paper代寫參考范文，主要內(nèi)容是講述當(dāng)今競爭激烈的市場要求公司盡可能有效地提供產(chǎn)品和服務(wù)。分銷策略是成功的關(guān)鍵。分銷網(wǎng)絡(luò)的關(guān)鍵組成部分之一是倉庫位置。選址決策被認(rèn)為是一項長期的商業(yè)戰(zhàn)略決策。正確的選址決策可以顯著改善業(yè)務(wù)流程和性能，并帶來相對于競爭對手的競爭優(yōu)勢（即成本節(jié)約、服務(wù)質(zhì)量等）。另一方面，如果做出了一個糟糕的選址決定，公司同樣會付出時間、金錢和機會。位置決策的環(huán)境是動態(tài)的，通常被描述為多標(biāo)準(zhǔn)決策。下面就一起來看一下這篇research paper代寫范例的具體內(nèi)容。

The effect of location decision on a business success

2.1 Introduction

Todays competitive market demands companies to deliver their products and services as effectively and efficiently as possible. The distribution strategy is the key to the success. One of the key components of a distribution network is warehouse location. Location decision is considered as a long-term business strategic decision. The correct location decision can resulted in significant improvement in business processes and performance, and bring competitive advantages (i.e. cost saving, service quality, etc.) over its competitors. On the other hand, if a poor location decision was made, it could equally cost the company time, money and opportunity. The location decision’s environment is dynamic and normally described as a multi-criteria decision.

Furthermore, the globalisation and the rapid evolution of information technology have changed the characteristics of location problems. There are two major trends in facility location selection accordingly to Yang and Lee (1997). First, there has been an increased interest to gain potential competitive edge in the global marketplace. Second, small to medium-sizes communities has become more attractive to many businesses as new facility location. These two trends are influenced by the more advanced communication technology, better transportation infrastructure system, liberalised trade between countries, and so on. This allows company to select their facilities where they think has the most advantages (i.e. in land cost, labour cost, skilled labour availability, etc.).

This chapter will start by identifying why a company needs to improve its logistics system, then defining the linkage between the organisation’s strategy and the logistics strategy, followed by the general roles of warehouse in distribution strategy. Then it will present the influencing location factors companies normally consider when they make location decisions. And finally in the latter section of this chapter, it will present literature reviews of decision aid techniques and model used in location decisions.

2.2 Logistics system and the changing business environment

Why do we need to change our logistics operations and strategy? The main reason why we need to change is because the environment we live in is constantly and rapidly changing. In order to survive in this unforgiving environment businesses are forced need to change. There are many factors given by Rushton, et al. (2006) including increasing customer demand, reducing product life cycle, changing technologies, increasing pressures from competitors, and so on. The pressures for change given by Rushton, et al. (2006) are illustrated by the figure 1.

Figure 1 Pressure influencing logistics systems

2.3 Logistics strategy

Logistics strategy should aim to establish the most appropriate blend of storage and transport at a given customer service level. Efficient logistics and distribution strategies should reduce the total logistics costs and must take into account the interactions of various the various replenishment activities in the distribution chain (Rushton, et al., 2006; Teo & Shu, 2004).

Chopra and Meindl (2004) suggest there are four drivers to a successful distribution system: (1) Facilities – location, capacity, operations methodology, and warehousing methodology; (2) Inventory – cycle inventory, safety inventory, seasonal inventory, and sourcing; (3) Transportation – mode of transportation, route and network design, and in-house or outsource decision; and (4) Information – push or pull, coordination and information sharing, forecasting and aggregate planning, and enabling technologies. Bowersox and Closs (1996) suggest similar points but they also add another driver which is ‘network design’. They also claim that classical economics often neglected the importance of facility location and overall network design. Similarly but in more details, Alling and Tyndall (1994) identify ten principles that make logistics operations successful. They are: (1) to link logistics to corporate strategy; (2) to organise logistics comprehensively; (3) to use the power of information technology; (4) to emphasize human resources – recognising the importance of quality human resources; (5) to form strategic alliances; (6) to focus on financial performance; (7) to target optimum service levels; (8) to manage the details – pay attention to details as it can be significant savings; (9) to leveraging logistics volume – through consolidating shipment volumes, inventories and the like; and (10) to measure and react to performance.

Furthermore, when considering a distribution strategy, warehousing strategy is an important part and typically the decision makers or logistics planners has to answer these questions (1) should warehousing facilities be owned, leased or rented, (2) what is the optimal size and number of warehouses, (3) what are the optimal locations for warehouses, (4) what product line should be stocked at each warehouse location, and what market areas should be serviced from each warehouse location. (Stock & Lambert, 2001; Bowersox & Closs, 1996; Simchi-Levi, et al., 2003; Bowersox & Closs, 1996; Geoffrion & Powers, 1995; Bender, 1994; Stock & Lambert, 2001; Greasley, 2009)

Matching logistics strategy to business strategy

The important key to achieving the strategic fit is the ability of the company to find a balance between responsiveness and efficiency that best matches the business strategy. Whatever strategies chose to implement by the company, there will be impacts. And the impact of the selected logistics and distribution strategy has to be assessed against the business strategy. Often these may involve undertaking some qualitative analysis where it is impossible to derive good quantitative measures. The main areas of where this will impact, they are (Rushton, et al., 2006): a) Capital costs – this is the costs of new facilities, new equipments, and so on. In certain situations capital constraints can exclude otherwise attractive options; b) Operating costs – the minimum operating cost is often the main criterion for selection between options. In some cases increased operating costs can be accepted in the light of future flexibility; c) Customer service – Although options should have been developed against customer service targets, the selected short list must be examined for the customer service level achieved. The balance of the mix might have changed in an effort to reduce costs. Stock held close to the customer might need to be increased to improve service reliability.

2.5 Obstacles to achieving strategic Fit

As many as there are many factors and influences to achieving the strategic fit in the supply chain, there are also many obstacles to achieving the same goal as Chopra and Meindl (2004) and few other writers mention. Few examples of the obstacles to strategic fit are: a) the variety of products – the increasing variety of products tends to raise uncertainty and uncertainty tends to raise costs and reduce responsiveness within the system; b) the product lifecycles – the decreasing product lifecycles also tends to raise uncertainty and reduce the window of opportunity to achieving strategic fit; c) the increasingly demanding customer – customers demand for faster fulfilment, better quality, and better value for money for the product they buy, companies must be able to provide these just to maintain their businesses; d) the fragmentation of supply chain ownership – less vertically integrated structure can result in difficult coordination to achieving strategic fit; e) the effect of globalization – difficulties raised by the invasion of foreign players. It is noticed that these factors are the same factors which drives the need to improve logistics system as determined in section 2.2.

2.6 The logistics and distribution planning framework

Many authors agree on the first and the most important step, when planning the logistics and distribution, which is to identify the objective and strategies of the organization. Then it follows by the second step which is to gain a detailed understanding of the present position of the system. The rests of the procedures are identifying the options, analysing the options, comparing and evaluating the results, and developing a planning and implementation. A diagram illustrating the approach to distribution planning by Rushton, et al. (2006) is shown in the figure 3 below.

Figure 2: An approach to logistics and distribution planning (Rushton, et al., 2006)

2.7 Optimal number of warehouses

The optimal number of warehouses can be found by using a costing model, a model which takes into account of variable costs, particularly the transport and operating costs. Few facilities give low cost for inward transport, but high cost for outward transport, as they are, on average, further away from customers. On the other hand, more number of facilities can give higher cost for inward transport, but the cost for outward transport is lower, as they are, on average, closer to customers. Another cost that varies with the number of facility is the operating costs. Higher number of facilities means the company has to bear more expensive cost to operating these facilities. Operating costs also vary with facility size. Generally, larger facilities give the economies of scale; however, this is not always the case. Higher cost from operating larger facilities may come from the cost of supervision, communication, inefficiency and so on (Attwood & Attwood, 1992; Bowersox & Closs, 1996; Waters, 2003; Chopra & Meindl, 2004; Rushton, et al., 2006). Figure 4 graphically illustrates the relationships between number of facilities and costs incurred.

Figure 3 Relationship between costs and numbers of facilities.

The need to hold inventories

Prior to planning and designing logistics and distribution system, it is very important to be aware of the reason why a company need to hold stock. The most common objective of a supply chain is to efficiently balancing demand and supply. As most people understand that it is impossible to precisely synchronise or balance the requirements of demand with the fluctuations of supply. Therefore stocks are there to provide buffer between supply and demand. Rushton, et al. (2006) reviews the important reasons to stock, as follows: a) to keep down production costs – keeping production to run as long as possible, as the costs of setting up machine is often expensive; b) to accommodate variation in demand – to avoid stock-outs by holding some level of safety stock; c) to take account of variable supply (lead) times – to cover any delays of supplies from producers and suppliers; d) to reduce buying costs – often there are administrative cost of placing an order, holding additional inventory can reduce these costs; e) to take advantage of quantity discounts – often goods are offered at a cheaper cost per unit if they are ordered in large quantity; f) to account for seasonal fluctuations – certain products are popular in a certain time of the year, retailer normally pile-up inventory during low demand season to cater the demand in high season; g) to allow for price fluctuations/speculation – the price of certain products, steel for instance, fluctuate due to variety of reasons. Some companies buy in large quantity to cater this; h) to help the production and distribution operations run more smoothly – stock is held to ‘decouple’ two different activities; i) to provide customers with immediate service – stocks enables companies to provide goods and service as soon as they are required to maximise the sales opportunity. This is essential in highly competitive markets; j) to minimise production delays caused by lack of spare parts – Breakdowns of machineries required to produce goods or services can be very costly to business. Having spare parts to fix the machineries as soon as it breakdowns is an advantage; k) to facilitate the production process by providing semi-finished stocks between different processes (Work-in-Progress).

2.9 Roles of warehouse

Why businesses need warehouse? There are many reasons why business needs warehouses. Warehouse has many roles apart from providing storage and supplying the materials or finished goods to producers or retailers as reviewed in the previous section. In fact warehouse has many other roles and functionalities which can be classified on the basis of economics and service accordingly to Bowersox and Closs (1996). On the basis of economics, a warehouse is economically justified when the total logistical costs are reduced by providing the facility. On the basis of service, a warehouse is justified when the overall logistical system can provide a better service, in terms of time and place capability.

Here are some common roles of a warehouse (Bowersox & Closs, 1996; Higginson & Bookbinder, 2005; Rushton, et al., 2006):

Role as a make-bulk/break-bulk consolidation centre – making bulk and breaking bulk are traditional functions of a warehouse/DC. In a break-bulk facility, large incoming loads are aggregated, often for product mixing and to create consolidated out- bound shipments. A make-bulk facility, or consolidation centre, com- bines small quantities of several products in fewer, larger assortments.

Role as a cross-docking station – Cross-docking is a process where the product is received, occasionally combined with different products going out to the same destination, and then shipped at their earliest opportunity without being stored. Cross-docking has many benefits, including: faster product flow, no inventory pile-up, reduced product handling, and reduce cost due to elimination of those activities.

Role as a transhipment facility – transhipment refers to a process of taking a shipment out of one vehicle and loading it onto another. It only occurs when there is a good reason to change transportation modes or vehicle types.

Role as an assembly facility – Hewlett Packard’s distribution centre is a good example of the role as an assemble facility. It also benefits from the idea of postponement which allows product differentiation until later stages. Products are designed to use generic parts and assemble at the warehouse.

Role as a product-fulfilment centre – the major function is to find the products that are ordered and directly deliver them to the final customer. Amazon.com warehouse is a good example.

Role as depot for returned goods – the major functions are to inspect and separate the returned good into those that can be repaired, repackaged, resale, or recycled.

2.10 Transportation

Accordingly to Chopra and Meindl (2004), the target level of service the company sets determines the role of transportation in a company competitive strategy. If the company is targeting customers whose main criterion is price, then the company can use transportation to lower the cost of the product at the expense of reponsiveness. But more often companies tries to achieve the right balance between efficiency and responsiveness using both inventory and transportation.

Often in logistics plannings, decision to make to make any changes based on the costs of transportation. Accordingly to Rushton, et al. (2006), the transportation costs can be broken into three main types. The first one is the fixed costs – these costs must be borne whether the vehicles run for 10 or 100 kilometres and might include the depreciations of the vehicles, the licence fees, the insurance, etc. And these may vary from one vehicle to another depending on various reasons. The second type is the variable costs – these costs vary in relation to the activity of the vehicles, i.e. how far the vehicle travelled. The most obvious example of a variable of cost is the fuel cost. And the last type is the overhead costs – these costs are indirect costs that are borne by the whole fleet of vehicles. They may be the usual business overheads that are required to run the vehicles, i.e. staff salaries, telephone, internet, and other administrative expenses.

2.11 Location decision objectives

Warehouse site selection is a complex process involving multiple, both qualitative and quantitative, criteria. And often location decisions have more than one objective depending on the organisation’s objectives and strategies. Current, et al., (1990) classified the objectives for facility location problems into four general categories namely: (1) Cost minimisation; (2) Demand Oriented; (3) Profit maximisation; (4) Environment concern, and often these objectives are found to overlap each other. For retailing business, cost minimisation and profit maximisation are often the main objectives.

2.12 The influences of warehouse site location selection

It is important to effectively identify potential locations for the new warehouses. Typically, these locations must satisfy a variety of conditions and the potential locations should meet all the requirements. The potential locations should take into account the future demand and that the decision should have an impact on the firm for at least the next three to five years (Simchi-Levi, et al., 2003).

Many authors (Chase, et al., 2004; Barnes, 2008) suggested that the choice of facilities location is influenced by two principles. The first one is the need to locate close to customer due to time-based competition, trade agreement, and transportation cost. And the second one is the need to locate close to the access to resources such as labour, raw material, and specialist skills and capabilities. Often the two principles are taken into account when an organization makes a decision on the choice of location. The characteristics of operations of business (i.e. Manufacturer or service provider) will govern the weight of factors should be taken into account.

Barnes (2008) looked at the location decision on the international perspective where the influential facility location factors are more in numbers and level of complexity. However, these factors can be adapted and used for domestic facility location. Here is the list of major factors which in themselves comprises of several sub-factors given by Barnes (2008): Costs; Labour characteristics; Infrastructure; Proximity to suppliers; Proximity to market/customers; Proximity to parent company facilities; Proximity to competition; Quality of life; Legal and regulatory framework; Economic factors; Government and political factors; Social and cultural factors; and Characteristic of a specific location.

Bowersox and Closs (1996) concentrated on the warehouse location analysis in the context of logistical network strategy. He discusses about three warehouse location patterns namely Market-Positioned Warehouse, Manufacturing-Positional Warehouse, and Intermediately Positioned Warehouse. They imply the similar idea of the two principles suggested by Chase, et al. (2004) and Barnes (2008). They also discussed the warehouse location from the viewpoint of transportation economies and from the viewpoint of inventory economies. Furthermore they incorporate the concept of Least-Total-Cost system where the sum of total inventory cost and transportation cost is minimal to design the warehouse network.

The conditions or attributes of potential warehouse locations reviewed from many literatures are summarised as follows:

Site-related factors

Regional factors

Land cost/size/soil characteristics/ drainage

Proximity to market

Construction costs/leasing cost/renting costs

Proximity to suppliers

Transportation facilities/cost

Proximity to competitors

Zoning restrictions

Proximity to industry

Community factors

Geographical characteristics

Quality of life/cost of living

weather characteristics

Public facility accessibility

Labour cost/availability/skill

Taxes

Energy availability/cost

Environment regulation

Telecommunication facility

Local government support/incentives

Political matters and regulation

Sustainability

Transportation infrastructure

2.13 Methods and techniques in facility location problems

In this section, we will review the methods, techniques, and approaches found in a number of literatures.

Bowersox and Closs (1996) claim that a sophisticated modelling and analysis techniques are required in location decision because the location analysis is very complex and data-intense. The complexity is created because of the number of locations multiplied by the alternative location sites multiplied by the stocking strategies for each location. Meanwhile, the data intensity is caused by the requirement of detailed demand and transportation information. Furthermore, the facility site selection process is complicated by the impact of environment legislation and related political issues (Bowersox & Closs, 1996).

Thai and Grewal (2005) suggest the conceptual framework of location selection for distribution centre that consists of three main stages. The first stage is a general geographical area for distribution centre is identified based on the Centre-of-Gravity principle. The second stage is the identification of location alternatives of distribution centre and associate gateway airports/seaports. At this stage a qualitative approach should be applied. The third and final stage concentrates on the specific site selection based on the quantitative approach, i.e. The distribution centre should be place where the integration of volumes transported and distance involved is minimum and also the total distribution cost is minimum.

2.13.1 Decision-aid Techniques and Models

Several operations management books (Stevenson, 2007; Barnes, 2008; Greasley, 2009) have their sections on facility location selection techniques and some common influencing factors as reviewed in the previous section. Accordingly to works of Simchi-Levi, et al. (2003), Rushton, et al. (2006), and Bowersox and Closs (1996), there are three categories for tools used to support location analysis. The first type is the analytic techniques. The second type techniques are the mathematical optimisation techniques which can be subdivided into two types: the exact algorithms that find least-cost solution; and the heuristics algorithms that find good solution. And the third type of techniques is simulation models that provide a mechanism to evaluate specific design alternatives created by designer. The simulation models will not, however, be included in the discussion.

Accordingly to Randhawa and West (1995), the facility location problem can be approached by considering the location search space as continuous or discrete. Continuous space allows facilities to be located anywhere in the two-dimensional space; it normally assumes that the transportation costs are proportional to some distance measure between the facilities. Though easy to solve, the continuous approach may yield impractical results. The discrete space approach limits the number of possible locations to a finite set of predetermined sites, and the transportation costs are not necessarily function of distances.

Four common types of techniques found on these books namely: (1) the Centre of Gravity Method – i.e. finding a location that minimises the distribution costs; (2) the Locational Cost-Volume analysis – i.e. comparing the total costs between location alternatives by graph plotting; (3) the Factor Scoring – i.e. finding the location alternative with highest composite score; and (4) the Transportation model – i.e. a linear programming model that shows location alternative with the most optimal solution (the lowest costs).

2.13.2 The Centre of Gravity Method

The Centre of Gravity Method (CoG) is a method for locating a distribution centre that minimises the distribution costs. The main assumption of this method is the distribution cost is a linear function of the distance and the quantity transported, and that the quantity transported is fixed for the duration of the journey (Stevenson, 2007 & Greasley, 2009). The locations of destinations are presented on the map with coordinate X and Y in an accurate scale. The location of the distribution point should be located at the centre of gravity of the coordination calculated by these following equations:

Where

= Quantity to be transported to destination i

= x coordination of destination i

= y coordination of destination i

= x coordinate of centre of gravity

= y coordinate of centre of gravity

This technique is commonly used to solve location problems at a macro level. The method is applied to solve location problems in many fields other than location of a distribution centre such as school, fire centres, community centres, and such, taking into consideration location of hospitals, population density, highways, airports, and businesses (Stevenson, 2007).

Bender (1994) argues that the CoG approach had became obsolete because of the replacement of other computerised approach including linear programming. He also discusses the limitation of the approach which ignores all constraints, such as capacity, financial, operational, legal, and all cost other than transportation. It is also assume that all the transportation costs are directly proportional to distance, and independent of the direction of traffic.

2.13.3 Locational Cost-Volume Analysis

This method is an economic comparison of location alternatives which involves determining the fixed and variable costs for each location alternative. The method indicates which location is suitable for a particular volume level by analysing the mix of fixed and variable costs. The fixed cost plus variable costs line is plotted for each location alternative on the graph and the location with the lowest total cost line at the expected volume level is chosen. A total revenue line can also be plotted on the same graph to compare which location alternative has the earliest breakeven point if the objective is to consider the quickest breakeven location (Stevenson, 2007). The equation for expressing the cost is:

Where

TC = Total distribution cost

VC = Variable cost per unit

X = Number of units produced

FC = Fixed costs

This type of economic analysis is very common tool to compare which options have the highest rate of return and is not only limited to location problems. However, Stevenson (2007) suggests that, in most situations, it is very important that other factors other than costs must also be considered. The Locational cost-volume analysis alone is not sufficient to make decision.

2.13.4 Factor Rating Method

The Factor Scoring method is sometimes known as weighted scoring or point rating, which attempts to take a range of considerations into account when choosing a location. Then technique starts by indentifying the relevant factors, then assign a weight to each factor that indicate the importance compared with other factors, given that all the weight sum up to one. Scores then have to be given by decision makers to each factor for all location alternatives. The total weighted scores for each location alternative are then calculated by multiplying the factor weight by the score for each factor, and sum the results for each location alternative. The alternative with highest score is chosen unless it fails to meet the minimum threshold, if there is one (Stevenson, 2007).

The drawback of this method is identifying and determining the appropriate factors and weighting for each factor. Factors like quality of living and labour attitude are intangible factors and hard to quantify. Greasley (2009) suggested an approach to compare the tangible and intangible factors by conducting an ‘intangible factors only assessment’ by the method, and then determine if the difference between the intangible scores is worth the cost of the difference in tangible costs between the location alternatives.

Data collection, statistical estimates, optimization and simulation models, and economic analysis are some of the methods used to assess quantitative attributes. Qualitative attributes represent subjective factors for which it is generally difficult to define a natural measurement scale. Descriptive classes or interval scales (for example, 0 to 10) can be established to enable a numerical value to be assigned to represent how a site scores with respect to a particular attribute (Randhawa & West, 1995).

Linear Programming and location problems

Linear Programming is one of the most widely used strategic and tactical logistics planning tools. The transportation model helps decision maker to decide the facility location based on the transportation costs. The model is very useful as it can compare the resulting total costs for each location alternative. Other costs like production costs can also be included in the model by determining the cost on a per-unit basis for each location. There are three major pieces of information needed to use the model as following (Stevenson, 2007; Balakrishman, et al., 2007): a) list of origins and each one’s supply quantity per period; b) list of the destinations and each ones’ demand per period; and c) the unit cost of transporting items from each origin to each destination. The method can be used to solve for optimal or near-optimal locations. Even though the optimisation models are designed to provide an optimal solution, they can be used to analyze a problem under different scenarios (different combinations of constraints and cost parameters). The result would be a set of location alternatives that are the preferred choices under different operating conditions. Furthermore, examination of a solution will generally result in the identification of more than one specific site. Such sites may then be further analyzed and compared using a multi-criteria model (Randhawa & West, 1995).

There are many types of mathematical programming models and they can be classified accordingly a variety of conditions. Aikens (1985) classified distribution location models accordingly to: a) whether the underlying distribution network (arcs and/or modes) is capacitated or incapacitated; b) the number of warehouse echelons, or levels (zero, single, or multiple); c) the number of commodities (single or multiple); d) the underlying cost structure for arcs and/or nodes (linear or nonlinear); e) whether planning horizon is static or dynamic; f) the patterns of demand (e.g. deterministic or stochastic, influence of location, etc.); g) The ability to accommodate side constraints (e.g. single-sourcing, choice of only one from candidate subset, etc.).

Aiken (1985) gives some examples of types of distribution location mathematical programming models: a) Simple incapacitated facility location model; b) Simple incapacitated multi-echelon facility location model; c) Multi-commodity incapacitated facility location model; d) Dynamic incapacitated facility location model; e) Capacitated facility location models; f) Generalised capacitated facility location model; g) Stochastic capacitated facility location model; and h) Multi-commodity capacitated single-echelon facility location model.

Diabat, et al. (2009) also show that the techniques can be applied to solve location-inventory problems which finds the number of warehouses to establish , their locations, the customers that are assigned to each warehouse, and the size and time of orders for each warehouse so as to minimise the sum of inventory. Melo, et al. (2009) review many literatures related to facility location problem that show that linear prog

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選址決策對企業(yè)成功的影響

2.1簡介

當(dāng)今競爭激烈的市場要求公司盡可能有效地提供產(chǎn)品和服務(wù)。分銷策略是成功的關(guān)鍵。分銷網(wǎng)絡(luò)的關(guān)鍵組成部分之一是倉庫位置。選址決策被認(rèn)為是一項長期的商業(yè)戰(zhàn)略決策。正確的選址決策可以顯著改善業(yè)務(wù)流程和性能，并帶來相對于競爭對手的競爭優(yōu)勢（即成本節(jié)約、服務(wù)質(zhì)量等）。另一方面，如果做出了一個糟糕的選址決定，公司同樣會付出時間、金錢和機會。位置決策的環(huán)境是動態(tài)的，通常被描述為多標(biāo)準(zhǔn)決策。

此外，全球化和信息技術(shù)的快速發(fā)展改變了位置問題的特點。根據(jù)Yang和Lee（1997），設(shè)施選址有兩個主要趨勢。首先，人們對在全球市場上獲得潛在競爭優(yōu)勢的興趣越來越大。其次，作為新設(shè)施的所在地，中小型社區(qū)對許多企業(yè)更有吸引力。這兩種趨勢受到更先進的通信技術(shù)、更好的交通基礎(chǔ)設(shè)施系統(tǒng)、國家間貿(mào)易自由化等因素的影響。這使公司能夠選擇他們認(rèn)為最具優(yōu)勢的設(shè)施（即土地成本、勞動力成本、熟練勞動力可用性等）。

本章將首先確定公司為什么需要改進其物流系統(tǒng)，然后定義組織戰(zhàn)略和物流戰(zhàn)略之間的聯(lián)系，然后定義倉庫在分銷戰(zhàn)略中的一般作用。然后，它將介紹公司在做出選址決策時通常考慮的影響選址的因素。最后，在本章的后半部分，它將介紹用于位置決策的決策輔助技術(shù)和模型的文獻綜述。

2.2物流系統(tǒng)和不斷變化的商業(yè)環(huán)境為什么我們需要改變我們的物流運營和戰(zhàn)略？我們需要改變的主要原因是我們生活的環(huán)境在不斷快速地變化。為了在這種無情的環(huán)境中生存，企業(yè)被迫改變。Rushton等人（2006）給出了許多因素，包括增加客戶需求、縮短產(chǎn)品生命周期、改變技術(shù)、增加競爭對手的壓力等。Rushton等（2006）提出的變革壓力如圖1所示。

圖1影響物流系統(tǒng)的壓力

2.3物流戰(zhàn)略

物流戰(zhàn)略應(yīng)旨在在給定的客戶服務(wù)水平上建立最合適的存儲和運輸組合。高效的物流和分銷策略應(yīng)降低總物流成本，并必須考慮分銷鏈中各種補貨活動的相互作用（Rushton等人，2006；Teo&Shu，2004年）。

Chopra和Meindl（2004）認(rèn)為，成功的分銷系統(tǒng)有四個驅(qū)動因素：（1）設(shè)施——位置、容量、運營方法和倉儲方法；（2） 庫存——周期庫存、安全庫存、季節(jié)性庫存和采購；（3） 運輸——運輸方式、路線和網(wǎng)絡(luò)設(shè)計，以及內(nèi)部或外包決策；以及（4）信息——推送或拉動、協(xié)調(diào)和信息共享、預(yù)測和綜合規(guī)劃以及賦能技術(shù)。Bowersox和Closs（1996）提出了類似的觀點，但他們也增加了另一個驅(qū)動因素，即“網(wǎng)絡(luò)設(shè)計”。他們還聲稱，古典經(jīng)濟學(xué)經(jīng)常忽視設(shè)施位置和整體網(wǎng)絡(luò)設(shè)計的重要性。類似地，但更詳細(xì)地說，Alling和Tyndall（1994）確定了使物流運營成功的十條原則。它們是：（1）將物流與企業(yè)戰(zhàn)略聯(lián)系起來；（2） 全面組織物流；（3） 利用信息技術(shù)的力量；（4） 強調(diào)人力資源——認(rèn)識到優(yōu)質(zhì)人力資源的重要性；（5） 形成戰(zhàn)略聯(lián)盟；（6） 注重財務(wù)業(yè)績；（7） 以達(dá)到最佳服務(wù)水平為目標(biāo)；（8） 管理細(xì)節(jié)——注意細(xì)節(jié)，因為這可以節(jié)省大量費用；（9） 利用物流量——通過整合運輸量、庫存等；以及（10）測量性能并對其作出反應(yīng)。

此外，在考慮分銷戰(zhàn)略時，倉儲戰(zhàn)略是一個重要的組成部分，通常決策者或物流規(guī)劃者必須回答以下問題：（1）倉儲設(shè)施應(yīng)為自有、租賃或租賃的，（2）倉庫的最佳規(guī)模和數(shù)量是多少，（3）倉庫的最優(yōu)位置是什么，（4）每個倉庫位置應(yīng)儲備什么產(chǎn)品線，以及每個倉庫位置應(yīng)該為哪些市場區(qū)域提供服務(wù)。（Stock&Lambert，2001；Bowersox&Closs，1996；Simchi Levi等人，2003；Bowersox&Closs，96；Geoffrion&Powers，1995；Bender，1994；Stock&Lanbert，2001；Greasley，2009）

將物流戰(zhàn)略與商業(yè)戰(zhàn)略相匹配實現(xiàn)戰(zhàn)略匹配的重要關(guān)鍵是公司能夠在響應(yīng)能力和效率之間找到最符合業(yè)務(wù)戰(zhàn)略的平衡。無論公司選擇實施何種戰(zhàn)略，都會產(chǎn)生影響。必須根據(jù)業(yè)務(wù)戰(zhàn)略評估所選物流和分銷戰(zhàn)略的影響。通常，這些可能涉及進行一些定性分析，而這些分析無法得出良好的定量指標(biāo)。這將影響的主要領(lǐng)域是（Rushton等人，2006）：a）資本成本——這是新設(shè)施、新設(shè)備等的成本。在某些情況下，資本限制可能會排除其他有吸引力的選擇；b） 運營成本——最低運營成本通常是選擇方案的主要標(biāo)準(zhǔn)。在某些情況下，考慮到未來的靈活性，可以接受增加的運營成本；c） 客戶服務(wù)——盡管應(yīng)該根據(jù)客戶服務(wù)目標(biāo)制定選項，但必須檢查所選的短名單，以確定所達(dá)到的客戶服務(wù)水平。為了降低成本，組合的平衡可能已經(jīng)發(fā)生了變化。可能需要增加靠近客戶的庫存，以提高服務(wù)可靠性。2.5實現(xiàn)戰(zhàn)略匹配的障礙正如Chopra和Meindl（2004）以及其他作者很少提及的那樣，盡管在供應(yīng)鏈中實現(xiàn)戰(zhàn)略匹配有許多因素和影響，但實現(xiàn)同樣目標(biāo)也有許多障礙。戰(zhàn)略匹配障礙的例子很少：a）產(chǎn)品的多樣性——產(chǎn)品種類的增加往往會增加不確定性，而不確定性往往會增加成本并降低系統(tǒng)內(nèi)的響應(yīng)能力；b） 產(chǎn)品生命周期——產(chǎn)品生命周期的縮短也往往會增加不確定性，減少實現(xiàn)戰(zhàn)略匹配的機會窗口；c） 要求越來越高的客戶——客戶要求他們購買的產(chǎn)品實現(xiàn)更快、質(zhì)量更好、物有所值，公司必須能夠提供這些產(chǎn)品來維持其業(yè)務(wù)；d） 供應(yīng)鏈所有權(quán)的碎片化——縱向一體化程度較低的結(jié)構(gòu)可能導(dǎo)致難以協(xié)調(diào)以實現(xiàn)戰(zhàn)略匹配；e） 全球化的影響&外國參與者的入侵帶來的困難。值得注意的是，這些因素與第2.2節(jié)中確定的推動物流系統(tǒng)改進需求的因素相同。

2.6物流和配送規(guī)劃框架

許多作者一致認(rèn)為，在規(guī)劃物流和配送時，第一步也是最重要的一步是確定組織的目標(biāo)和戰(zhàn)略。然后是第二步，即詳細(xì)了解系統(tǒng)的當(dāng)前位置。程序的其余部分是確定備選方案、分析備選方案、比較和評估結(jié)果以及制定規(guī)劃和實施。下圖3展示了Rushton等人（2006）的配電規(guī)劃方法。

圖2：物流和配送規(guī)劃方法（Rushton等人，2006年）

2.7倉庫的最佳數(shù)量

倉庫的最佳數(shù)量可以通過使用成本計算模型來找到，該模型考慮了可變成本，特別是運輸和運營成本。很少有設(shè)施提供低成本的向內(nèi)運輸，但提供高成本的向外運輸，因為它們平均離客戶更遠(yuǎn)。另一方面，更多數(shù)量的設(shè)施可能會給入境運輸帶來更高的成本，但出境運輸?shù)某杀靖停驗樗鼈兤骄x客戶更近。另一個隨設(shè)施數(shù)量而變化的成本是運營成本。更多的設(shè)施意味著公司必須承擔(dān)更昂貴的運營成本。運營成本也因設(shè)施規(guī)模而異。一般來說，較大的設(shè)施具有規(guī)模經(jīng)濟性；然而，情況并非總是如此。運營大型設(shè)施的更高成本可能來自監(jiān)督、溝通、效率低下等方面的成本（Attwood&Attwood，1992；鮑爾索克斯和克洛斯，1996年；Waters，2003年；Chopra和Meindl，2004年；Rushton等人，2006年）。圖4以圖形方式說明了設(shè)施數(shù)量與產(chǎn)生的成本之間的關(guān)系。

圖3成本與設(shè)施數(shù)量之間的關(guān)系。

需要持有庫存

在規(guī)劃和設(shè)計物流和配送系統(tǒng)之前，了解公司需要庫存的原因是非常重要的。供應(yīng)鏈最常見的目標(biāo)是有效地平衡需求和供應(yīng)。正如大多數(shù)人所理解的那樣，不可能使需求需求與供應(yīng)的波動精確同步或平衡。因此，庫存是為了在供應(yīng)和需求之間提供緩沖。Rushton等人（2006）回顧了庫存的重要原因，如下所示：a）降低生產(chǎn)成本——盡可能長時間地保持生產(chǎn)運行，因為設(shè)置機器的成本往往很高；b） 適應(yīng)需求的變化——通過持有一定水平的安全庫存來避免缺貨；c） 考慮可變的供應(yīng)（交付周期），以彌補生產(chǎn)商和供應(yīng)商供應(yīng)的任何延誤；d） 為了降低購買成本——通常有下訂單的管理成本，持有額外的庫存可以降低這些成本；e） 利用數(shù)量折扣——如果大量訂購，通常每件商品的價格會更低；f） 考慮到季節(jié)性波動——某些產(chǎn)品在一年中的某個時間很受歡迎，零售商通常在需求淡季堆積庫存以滿足旺季的需求；g） 考慮到價格波動/投機——某些產(chǎn)品的價格，例如鋼鐵，由于各種原因而波動。一些公司為了迎合這一需求而大量購買；h） 幫助生產(chǎn)和分銷業(yè)務(wù)更順利地運行&庫存是為了“脫鉤”兩種不同的活動；i） 為客戶提供即時服務(wù)–庫存使公司能夠在需要時盡快提供商品和服務(wù)，以最大限度地提高銷售機會。這在競爭激烈的市場中至關(guān)重要；j） 以最大限度地減少因缺乏備件而造成的生產(chǎn)延誤——生產(chǎn)商品或服務(wù)所需的機械故障可能會給企業(yè)帶來高昂的成本。一旦機器發(fā)生故障，就有備件來修理是一種優(yōu)勢；k） 通過在不同過程之間提供半成品庫存來促進生產(chǎn)過程（在制品）。

2.9倉庫的作用

為什么企業(yè)需要倉庫？企業(yè)需要倉庫的原因有很多。倉庫除了提供儲存和向生產(chǎn)商或零售商供應(yīng)材料或成品外，還有許多作用，如前一節(jié)所述。事實上，倉庫還有許多其他角色和功能，可以根據(jù)Bowersox和Closs（1996）的經(jīng)濟和服務(wù)進行分類。從經(jīng)濟學(xué)的角度來看，當(dāng)通過提供設(shè)施降低總物流成本時，倉庫在經(jīng)濟上是合理的。在服務(wù)的基礎(chǔ)上，當(dāng)整個物流系統(tǒng)能夠在時間和地點能力方面提供更好的服務(wù)時，倉庫是合理的。

以下是倉庫的一些常見角色（Bowersox&Closs，1996；Higginson&Bookbinder，2005；Rushton等人，2006年）：

作為批量生產(chǎn)/散雜貨整合中心——批量生產(chǎn)和散雜貨是倉庫/DC的傳統(tǒng)功能。在散雜貨設(shè)施中，大量的進口貨物被聚集在一起，通常用于產(chǎn)品混合和創(chuàng)建合并的出口貨物。批量生產(chǎn)設(shè)施或整合中心將少量的幾種產(chǎn)品組合成更小、更大的產(chǎn)品組合。

作為交叉對接站——交叉對接是一個接收產(chǎn)品的過程，偶爾會與不同的產(chǎn)品組合到同一目的地，然后在最早的時間發(fā)貨，而不需要儲存。交叉對接有很多好處，包括：更快的產(chǎn)品流，沒有庫存堆積，減少了產(chǎn)品處理，并由于消除了這些活動而降低了成本。

作為轉(zhuǎn)運設(shè)施的作用——轉(zhuǎn)運是指將貨物從一輛車上取下并裝載到另一輛車的過程。只有當(dāng)有充分的理由改變運輸方式或車輛類型時，才會發(fā)生這種情況。

作為裝配廠的角色——惠普的配送中心就是裝配廠角色的一個很好的例子。它還受益于延期的想法，這允許產(chǎn)品差異化到后期階段。產(chǎn)品設(shè)計為使用通用零件，并在倉庫進行組裝。

作為產(chǎn)品履行中心，其主要職能是找到訂購的產(chǎn)品并直接交付給最終客戶。亞馬遜倉庫就是一個很好的例子。

充當(dāng)退貨倉庫——主要功能是檢查退貨并將其分為可維修、重新包裝、轉(zhuǎn)售或回收的貨物。

2.10運輸

根據(jù)Chopra和Meindl（2004），公司設(shè)定的服務(wù)目標(biāo)水平?jīng)Q定了運輸在公司競爭戰(zhàn)略中的作用。如果公司的目標(biāo)客戶的主要標(biāo)準(zhǔn)是價格，那么公司可以使用運輸來降低產(chǎn)品成本，而犧牲責(zé)任感。但更多的時候，公司試圖通過庫存和運輸來實現(xiàn)效率和響應(yīng)能力之間的正確平衡。

通常在物流規(guī)劃中，根據(jù)運輸成本做出任何改變的決定。根據(jù)Rushton等人（2006），運輸成本可分為三種主要類型。第一個是固定成本——無論車輛行駛10公里還是100公里，這些成本都必須承擔(dān)，可能包括車輛折舊、執(zhí)照費、保險等。根據(jù)各種原因，這些成本可能因車輛而異。第二類是可變成本——這些成本與車輛的活動有關(guān)，即車輛行駛的距離。成本變量最明顯的例子是燃料成本。最后一種是間接成本——這些成本是由整個車隊承擔(dān)的間接成本。它們可能是運營車輛所需的通常業(yè)務(wù)管理費用，即員工工資、電話、互聯(lián)網(wǎng)和其他管理費用。

2.11選址決策目標(biāo)

倉庫選址是一個復(fù)雜的過程，涉及多個定性和定量標(biāo)準(zhǔn)。根據(jù)組織的目標(biāo)和戰(zhàn)略，選址決策通常有多個目標(biāo)。Current等人（1990）將設(shè)施選址問題的目標(biāo)分為四大類，即：（1）成本最小化；（2） 以需求為導(dǎo)向；（3） 利潤最大化；（4） 環(huán)境問題，以及這些目標(biāo)往往相互重疊。對于零售企業(yè)來說，成本最小化和利潤最大化往往是主要目標(biāo)。

2.12倉庫選址的影響

有效地確定新倉庫的潛在位置非常重要。通常，這些位置必須滿足各種條件，潛在位置應(yīng)滿足所有要求。潛在地點應(yīng)考慮到未來的需求，該決定應(yīng)至少在未來三到五年內(nèi)對公司產(chǎn)生影響（Simchi Levi等人，2003）。

許多作者（Chase等人，2004年；Barnes，2008年）認(rèn)為，設(shè)施位置的選擇受到兩個原則的影響。第一個是由于基于時間的競爭、貿(mào)易協(xié)議和運輸成本，需要靠近客戶。第二個是需要靠近勞動力、原材料、專業(yè)技能和能力等資源的獲取途徑。當(dāng)一個組織對地點的選擇做出決定時，通常會考慮這兩個原則。業(yè)務(wù)運營的特點（即制造商或服務(wù)提供商）將決定應(yīng)考慮的因素的權(quán)重。

Barnes（2008）從國際角度研究了選址決策，其中影響設(shè)施選址的因素更多地是在數(shù)量和復(fù)雜程度上。然而，這些因素可以適用于國內(nèi)設(shè)施的位置。以下是主要因素列表，其本身包括Barnes（2008）給出的幾個子因素：成本；勞動特點；基礎(chǔ)設(shè)施接近供應(yīng)商；接近市場/客戶；靠近母公司設(shè)施；接近競爭；生活質(zhì)量；法律和監(jiān)管框架；經(jīng)濟因素；政府和政治因素；社會和文化因素；以及特定位置的特征。

Bowersox和Closs（1996）專注于物流網(wǎng)絡(luò)戰(zhàn)略背景下的倉庫選址分析。他討論了三種倉庫定位模式，即市場定位倉庫、制造定位倉庫和中間定位倉庫。它們暗示了Chase等人（2004）和Barnes（2008）提出的兩個原則的相似思想。他們還從運輸經(jīng)濟和庫存經(jīng)濟的角度討論了倉庫位置。此外，他們結(jié)合了最小總成本系統(tǒng)的概念，其中總庫存成本和運輸成本的總和是最小的，以設(shè)計倉庫網(wǎng)絡(luò)。

從許多文獻中回顧的潛在倉庫位置的條件或?qū)傩钥偨Y(jié)如下：

現(xiàn)場相關(guān)因素

區(qū)域因素

土地成本/大小/土壤特性/排水

接近市場

建設(shè)成本/租賃成本/租賃費用

靠近供應(yīng)商

交通設(shè)施/成本

接近競爭對手

分區(qū)限制

接近工業(yè)

社區(qū)因素

地理特征

生活質(zhì)量/生活成本

天氣特征

公共設(shè)施可達(dá)性

勞動力成本/可用性/技能

稅

能源可用性/成本

環(huán)境法規(guī)

電信設(shè)施

地方政府支持/激勵措施

政治事務(wù)和監(jiān)管

持續(xù)性

交通基礎(chǔ)設(shè)施

2.13設(shè)施選址問題的方法和技術(shù)

在本節(jié)中，我們將回顧在許多文獻中發(fā)現(xiàn)的方法、技術(shù)和方法。

Bowersox和Closs（1996）聲稱，在位置決策中需要復(fù)雜的建模和分析技術(shù)，因為位置分析非常復(fù)雜，數(shù)據(jù)密集。造成復(fù)雜性的原因是，地點的數(shù)量乘以備選地點的數(shù)量，再乘以每個地點的庫存策略。同時，數(shù)據(jù)強度是由詳細(xì)的需求和運輸信息的要求引起的。此外，設(shè)施選址過程因環(huán)境立法和相關(guān)政治問題的影響而變得復(fù)雜（Bowersox&Closs，1996）。

Thai和Grewal（2005）提出了配送中心選址的概念框架，該框架由三個主要階段組成。第一階段是根據(jù)重心原則確定配送中心的一般地理區(qū)域。第二階段是確定配送中心和相關(guān)門戶機場/海港的位置備選方案。在這一階段，應(yīng)采用定性方法。第三個也是最后一個階段集中于基于定量方法的具體選址，即配送中心應(yīng)位于運輸量和所涉及距離的整合最小、總配送成本最小的地方。

2.13.1決策輔助技術(shù)和模型

幾本運營管理書籍（Stevenson，2007；Barnes，2008；Greasley，2009）都有關(guān)于設(shè)施選址技術(shù)和一些常見影響因素的章節(jié)，如前一節(jié)所述。根據(jù)Simchi Levi等人（2003）、Rushton等人（2006）以及Bowersox和Closs（1996）的工作，用于支持位置分析的工具有三類。第一類是分析技術(shù)。第二類技術(shù)是數(shù)學(xué)優(yōu)化技術(shù)，可細(xì)分為兩類：找到最小成本解的精確算法；以及找到良好解決方案的啟發(fā)式算法。第三類技術(shù)是模擬模型，它提供了一種機制來評估設(shè)計者創(chuàng)建的特定設(shè)計方案。然而，模擬模型將不包括在討論中。

根據(jù)Randhawa和West（1995），可以通過將位置搜索空間視為連續(xù)或離散來解決設(shè)施位置問題。連續(xù)空間允許設(shè)施位于二維空間中的任何位置；通常假設(shè)運輸成本與設(shè)施之間的距離成比例。雖然很容易解決，但連續(xù)方法可能會產(chǎn)生不切實際的結(jié)果。離散空間方法將可能位置的數(shù)量限制在有限的一組預(yù)定地點，并且運輸成本不一定是距離的函數(shù)。

這些書中有四種常見的技術(shù)，即：（1）重心法——即找到一個將分銷成本降至最低的地點；（2） 位置成本量分析——即通過繪圖比較位置備選方案之間的總成本；（3） 因素評分——即找到綜合得分最高的位置備選方案；以及（4）運輸模型——即一個線性規(guī)劃模型，顯示具有最優(yōu)化解決方案（最低成本）的位置備選方案。

2.13.2重心法

重心法（CoG）是一種將配送成本降至最低的配送中心定位方法。該方法的主要假設(shè)是配送成本是距離和運輸量的線性函數(shù)，并且運輸量在旅途中是固定的（Stevenson，2007&Greasley，2009）。目的地的位置以精確的比例顯示在地圖上，坐標(biāo)為X和Y。分布點的位置應(yīng)位于通過以下方程計算的坐標(biāo)重心處：

哪里

=運往目的地i的數(shù)量

=x目的地i的協(xié)調(diào)

=y目的地i的協(xié)調(diào)

=x重心坐標(biāo)

=y重心坐標(biāo)

這種技術(shù)通常用于在宏觀層面上解決位置問題。該方法適用于解決除配送中心位置以外的許多領(lǐng)域的位置問題，如學(xué)校、消防中心、社區(qū)中心等，同時考慮到醫(yī)院位置、人口密度、高速公路、機場和企業(yè)（Stevenson，2007）。

Bender（1994）認(rèn)為，CoG方法已經(jīng)過時，因為它取代了包括線性規(guī)劃在內(nèi)的其他計算機化方法。他還討論了該方法的局限性，該方法忽略了所有限制，如容量、財務(wù)、運營、法律以及除運輸外的所有成本。還假設(shè)所有的運輸成本與距離成正比，與交通方向無關(guān)。

2.13.3區(qū)位成本量分析

該方法是對位置備選方案的經(jīng)濟比較，包括確定每個位置備選方案中的固定成本和可變成本。該方法通過分析固定成本和可變成本的組合來指示哪個位置適合特定的容量水平。為圖表上的每個位置備選方案繪制固定成本加可變成本線，并選擇在預(yù)期容量水平下總成本線最低的位置。如果目標(biāo)是考慮最快的盈虧平衡地點，也可以在同一張圖上繪制總收入線，以比較哪個地點的備選方案具有最早的盈虧平衡點（Stevenson，2007）。表示成本的方程式為：

哪里

TC=總分銷成本

VC=單位可變成本

X=生產(chǎn)的單位數(shù)量

FC=固定成本

這種類型的經(jīng)濟分析是比較哪些選擇具有最高回報率的非常常見的工具，并且不僅限于位置問題。然而，Stevenson（2007）認(rèn)為，在大多數(shù)情況下，還必須考慮成本以外的其他因素，這一點非常重要。僅憑區(qū)位成本量分析不足以做出決策。

2.13.4因子評級方法

因素評分法有時被稱為加權(quán)評分或分?jǐn)?shù)評定，它試圖在選擇地點時考慮一系列因素。然后，該技術(shù)從識別相關(guān)因素開始，然后為每個因素分配一個權(quán)重，表明與其他因素相比的重要性，假設(shè)所有權(quán)重加起來為一。然后，決策者必須對所有位置備選方案的每個因素進行評分。然后通過將因子權(quán)重乘以每個因子的得分來計算每個位置備選方案的總加權(quán)得分，并對每個位置備選的結(jié)果求和。除非未能達(dá)到最低閾值（如果有的話），否則會選擇得分最高的備選方案（Stevenson，2007）。

這種方法的缺點是識別和確定適當(dāng)?shù)囊蛩匾约懊總€因素的權(quán)重。生活質(zhì)量和勞動態(tài)度等因素是無形的，難以量化。Greasley（2009）提出了一種比較有形和無形因素的方法，通過該方法進行“僅無形因素評估”，然后確定無形分?jǐn)?shù)之間的差異是否值得地點備選方案之間有形成本差異的代價。

數(shù)據(jù)收集、統(tǒng)計估計、優(yōu)化和模擬模型以及經(jīng)濟分析是用于評估定量屬性的一些方法。定性屬性代表主觀因素，通常很難定義自然測量量表。可以建立描述性類別或區(qū)間量表（例如，0到10），以便能夠指定一個數(shù)值來表示網(wǎng)站如何就特定屬性得分（Randhawa&West，1995）。

線性規(guī)劃與定位問題

線性規(guī)劃是應(yīng)用最廣泛的戰(zhàn)略和戰(zhàn)術(shù)后勤規(guī)劃工具之一。運輸模型有助于決策者根據(jù)運輸成本來決定設(shè)施的位置。該模型非常有用，因為它可以比較每個位置備選方案的總成本。通過確定每個地點的單位成本，也可以將生產(chǎn)成本等其他成本包括在模型中。使用該模型需要三個主要信息，如下所示（Stevenson，2007；Balakrishman等人，2007）：a）每個時期的來源和每個時期的供應(yīng)量列表；b） 目的地列表和每個時段的需求；以及c）將物品從每個來源地運輸?shù)矫總€目的地的單位成本。該方法可用于求解最優(yōu)或接近最優(yōu)的位置。即使優(yōu)化模型被設(shè)計為提供最佳解決方案，它們也可以用于分析不同場景（約束和成本參數(shù)的不同組合）下的問題。其結(jié)果將是一組位置備選方案，這些方案是不同操作條件下的首選方案。此外，對解決方案的檢查通常會識別出一個以上的特定地點。然后可以使用多標(biāo)準(zhǔn)模型對這些地點進行進一步分析和比較（Randhawa&West，1995）。

有許多類型的數(shù)學(xué)規(guī)劃模型，它們可以根據(jù)各種條件進行相應(yīng)的分類。Aikens（1985）對配電位置模型進行了相應(yīng)的分類：a）底層配電網(wǎng)絡(luò)（電弧和/或模式）是否有能力或無能力；b） 倉庫梯隊或級別的數(shù)量（零、單個或多個）；c） 商品數(shù)量（單個或多個）；d） 弧和/或節(jié)點的基本成本結(jié)構(gòu)（線性或非線性）；e） 規(guī)劃范圍是靜態(tài)的還是動態(tài)的；f） 需求模式（例如確定性或隨機性、位置的影響等）；g） 適應(yīng)側(cè)面約束的能力（例如，單一來源、僅從候選子集中選擇一個等）。

Aiken（1985）給出了一些配電網(wǎng)選址數(shù)學(xué)規(guī)劃模型類型的例子：a）簡單的無能力設(shè)施選址模型；b） 簡單的無能力多級設(shè)施選址模型；c） 多商品無能力設(shè)施選址模型；d） 動態(tài)喪失能力設(shè)施位置模型；e） 容量設(shè)施位置模型；f） 廣義容量設(shè)施位置模型；g） 隨機容量設(shè)施選址模型；以及h）多商品容量的單梯隊設(shè)施選址模型。

Diabat等人（2009）還表明，這些技術(shù)可以應(yīng)用于解決位置庫存問題，即找到要建立的倉庫數(shù)量、它們的位置、分配給每個倉庫的客戶以及每個倉庫的訂單規(guī)模和時間，以最大限度地減少庫存總額。Melo等人（2009）回顧了許多與設(shè)施選址問題有關(guān)的文獻，這些文獻表明

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