Revisión de los métodos, modelos y herramientas existentes para la selección de proveedores

The objective of this dissertation is to reflect the importance of supplier evaluation process, analyzing criteria that can be used to determinate the best supplier and developing different methods that help to make this decision. The market is changing and supplier selection approach has evolved from multiple suppliers to single supplier approach. In the past, the traditional approach used to consider multiple suppliers and one main criterion, the price. However, the market has moved towards contracting a single supplier selected by means of a multiple criteria. In 1960, Dickson created an exhaustive criteria list, which has been the reference for decades as the criteria to evaluate suppliers. This project has investigated the work carried out not only by Dickson but also by different authors that progressed in this area later on. Based on the research carried out, a new list has been developed. According to this investigation, quality, delivery, service and cost are the four most important criteria to evaluate suppliers. Furthermore, this investigation has identified that multi-criteria approach has some problems, since it is not easy to evaluate some of the criteria and sometimes they contradict each other. Therefore it is essential to record in advance what the company is looking for, and what the importance of each of the requirements is. Supplier selection process, which is described in Section 2, starts with the evaluation of the company needs, development of the requirements and selection criteria. Then, a market survey is carried out to identify a limited numbers of suppliers which will participate in the request for quotation (RFQ.) Once the bids are received, they are evaluated involving all company’s stakeholders. Finally, one or more companies are awarded as suppliers based on the final result. Section 3 depicts the evaluation criteria. There are plenty of methods to make the selection. This dissertation has focused on the following methods: Analytical Hierarchic Process (AHP), Analytic Network Process (ANP), Techniques for Order Preference by Similarity to an Ideal Solution (TOPSIS), Data Envelopment Analysis (DEA), Case-Based Reasoning (CBR) and Decision-Matrix Method. All of them are described in Section 4. Besides to explain the main important concept of each method, the methodology and the advantages and limitations, a review of authors, who propose extensions of this method, is carried out. Additionally this section includes a summary that was developed to include other existing methods for supplier evaluation. Finally, Section 5 provides a practical approach of these concepts, analyzing an existing real case of supplier selection in a successful energy sector company. It describes the company´s supplier selection process, the main criteria that are considered and an example of the technical evaluation of metallic structures to know with more detail tools that are used for that company.Ingeniería Industria