طراحی بر اساس خدمات مشتری از زنجیره تامین

The purpose of this study is to propose a framework by which service elements and a company's own strategies can be included in the “traditional”, cost-based design of the supply chain. The framework is demonstrated with a numerical example and it is based on integrating the analytic hierarchy process (AHP) and mixed integer programming (MIP). The target is to optimise a company's supply chain based on customer service requirements within the constraints of the supply chain.

Supply chain design has been an important part of the logistics decision-making process in companies. The importance of supply chain design has increased when more and more companies have realised the possibilities of gaining additional value for their customers by restructuring the supply chain. In fact, the growing awareness of the critical impact of supply chain management on an organisation's competitiveness, profitability and strategic advantage has made supply chain a truly strategic issue and it has received increased emphasis everywhere [1] and [2]. In addition, transportation as a part of logistics operations can be seen as a value-adding process that directly supports the primary goal of the organisation, which is to be competitive in terms of high-level customer service, competitive price and quality, and flexibility in responding to market demands [3]. The focus of logistics is increasingly turning towards providing better services for customers instead of minimising the total transportation or logistics costs or maximising the total profits of the supplier. Furthermore, logistics managers put more emphasis on controlling the whole logistics chain than concentrating on the problems of one echelon in the logistics process. One result of this is that there has been a growing interest on partnership and customer satisfaction issues. Firms are moving from a decoupled decision making process towards a more coordinated and integrated design and control of their supply chain to provide goods and services to the customer at low cost and high service levels [4]. Companies must also be able to efficiently respond to changes and reconfigure their resources to be able to compete and create profit by taking advantage of the opportunities occurring in the market place [5]. Historically, the three fundamental stages of the supply chain, procurement, production and distribution, have been managed independently and buffered by large inventories [4]. This policy has changed, especially manufacturers have increasingly given their attention to the management of logistics issues, in the pursuit of strategies that will give them competitive advantage [6]. It is a well-known fact, that it is possible to gain even more advantage by improving the logistics chain instead of improving the performance of one player in the chain. Therefore, the area of logistics research is nowadays not solely restricted to the production process itself but has spread into a wide range of subjects relating to the entire material flow into, within, and out of the organization [7]. Section 2 discusses the different approaches to the distribution network design problem. In Section 3, we present an approach to customer service-based design of the supply chain which is based on the integrated utilisation of the analytic hierarchy process and mixed integer linear programming.

The main problems in the traditional approaches for logistics network design are that they focus on the deliverer's point of view. Therefore, the traditional approaches concentrate on the objectives of one organisation in the supply chain and they normally exclude the strategic viewpoints of the deliverer. The intention of the present approach is based on integrating the analytic hierarchy process and mixed integer programming to expand the scope of the traditional approaches to a more customer oriented direction by implementing customers’ preferences on the decision process. In addition, the strategic viewpoints of the supplier, as well as the limitations and restrictions of the distribution network are included. The objective of the proposed approach is to provide a systematic and flexible framework for the customer service based design of the supply chain also taking into account the strategic decisions of the supplier. The potential problem related to the AHP-phase of the approach is the availability of the required information. As there are several nodes and links to be evaluated, it might be difficult to gather all the required data concerning all activities and their preferences and costs. However, the AHP-analysis can be carried out based on inadequate data as the AHP-method supports the use of subjective judgements. All assumptions and restrictions of linear programming (LP) and mixed integer programming (MIP) are faced, when a firm is implementing the approach. Therefore, it is important to be familiar with these assumptions and restrictions, which are well documented in the literature (see, for instance, [33]). In practise, the most significant restriction in the MIP-phase of the approach is the number of the 0/1 variables in the problem. These variables are needed for calculating the maximum number of see transport providers and hauliers as well as for counting the minimum required transportation volumes for truck carriers. The supply chain design is a strategic level problem, which means that the mathematical calculations for solving the problem are made e.g. annually. For this reason, there are enough time to carry out needed calculations for example during evenings or nighttime, which means that the number of the 0/1 variables is normally not limiting the use of the approach.