Hilda Saleh - Department of Mathematics, Central Tehran Branch, Islamic Azad University, Tehran, Iran

One of the most complicated decision making problems for managers is the evaluation and selection of supplier, which involves various criteria. There are several studies about supplier selection and evaluation by data envelopment analysis in the literature review. These studies do not focus on determining the number of supplier and they don’t propose any selection approach. In this paper we have focused on determining the number of suppliers and then proposing a method to select them.

Linear programming, symmetric trapezoidal fuzzy numbers, fuzzy simplex methods