As reported by De Boer et al. (2001), several decision-making steps make up the supplier selection process. At first, a preparation step is achieved by formulating the problem and the different decision criteria. After that, prequalification of potential suppliers and final choices are successively elaborated. De Boer et al. (2001, 2003) present an interesting overview of the literature on supplier selection models. It specifies the published works treating every stage of the selection process for every purchasing situation. In this section, every stage of the selection process (problem definition, decision criteria formulation, pre and final selection of potential suppliers) is demonstrated.
Due to shortened product life cycles, the search for new suppliers is a continuous priority for companies in order to upgrade the variety and typology of their products range. On the other hand, purchasing environments such as Just-In-Time, involve establishing close connections with suppliers leading to the concept of partnership, privileged suppliers, long-term agreement, etc. Thereby, decision makers are facing different purchasing situations that lead to different decisions. Consequently, in order to make the right choice, the purchasing process should start with finding out exactly what we want to achieve by selecting a supplier.