مروری بر روش های پشتیبانی از انتخاب تامین کننده

In this paper we present a review of decision methods reported in the literature for supporting the supplier selection process. The review is based on an extensive search in the academic literature. We position the contributions in a framework that takes the diversity of procurement situations in terms of complexity and importance into account and covers all phases in the supplier selection process from initial problem definition, over the formulation of criteria, the qualification of potential suppliers, to the final choice among the qualified suppliers. Moreover, we propose decision methods and techniques that previously have not been suggested in a purchasing context. The proposed methods specifically accommodate for buying situations for which few or no decision models were published so far. This paper extends previous reviews by Weber et al. (Eur. J. Oper. Res. 50 (1991) 2), Holt (Int. J. Project Mange. 16 (1998) 153) and Degraeve et al. (Eur. J. Oper. Res. 125 (1) (2000a) 34) in that it classifies the models in a framework developed by De Boer (Ph. D. Thesis, University of Twente, Enschede, The Netherlands, 1998) which recognises more steps in the buying process than only the final among qualified suppliers and accommodates for the diversity of procurement situations.

From our analysis of the methods currently being reported for supplier selection and the potential still left unused we draw the following conclusions. First, most attention has so far been paid to the choice phase in the supplier selection process. The phases prior to the choice phase (problem definition, criteria formulation and qualification) have received far less attention from researchers in operations research or purchasing and supply. The choice phase often being the most visible phase in the process, this is not very surprising. However, the quality of the choice phase is largely dependent on the quality of the steps prior to that phase. If purchasers strive for sound decision making they should also pay attention to these early steps. Our analysis did show that several suitable OR-methods are available for problem definition, formulation of criteria and qualification. Further research on the application of these methods therefore seems useful. Secondly, the vast majority of the publications found seem to have been written in the context of selecting a supplier for the purchase of a product to be used in a manufacturing environment. As most of the literature on the purchasing of services boils down to the summing up of relevant criteria and the ‘do's and don’ts’, the attentive reader has noticed that only one of the decision models (Degraeve et al., 2000) discussed here were developed in a service purchasing context. From a point of view of reflecting Purchasing's significance in sectors other than manufacturing, e.g. service industry, it would be worthwhile to investigate and illustrate the specifics of using decision methods in supplier selection in those areas as well. More specifically, further research on the suitability of decision methods for supplier selection in Government Procurement seems at place given the relatively higher need for justifying public procurement decisions and the European Union regulations on tendering. Apart from that however, the framework for classifying decision methods for supplier selection developed in this paper, and therefore the suitability of the various decision methods, does not depend on the specific industry or product or service under consideration. The differences between various sectors and products and services with regard to supplier selection ultimately boil down to different intrinsic meanings of selection criteria and different relevant importances of weights but these differences in itself do not determine the suitability of a certain decision method. Thirdly, the assignment of methods in our framework of supplier selection situations shows that not all methods are equally useful in every possible purchasing situation. However, the existing articles on methods for supplier selection do not sufficiently address this contextual issue. Often they assume, explicitly or implicitly, that their method is applicable in all purchasing contexts. At most, a reference is made to a particular industry in which a method has been empirically tested or the need to change the criteria considered when applying the method to another type of product. However, neither the specific industry nor the particular criteria at hand determine the usefulness of certain method. Our framework shows that more generic, situational characteristics like the number of suppliers available, the availability of historic information, the importance of the buy as well as the phasing and organisation of the whole supplier selection process are more determinative for the suitability of a certain method. In future research therefore, more attention should be paid to positioning new contributions in such a framework.