In Supply chain management, decision making for the selection of suppliers is of such a key importance that it has developed into a strategic objective for organizations in recent years. The issue of selecting a supplier, due to multiplicity and diversity of qualitative and quantitative indices, is a multi attribute decision making question and as a result, known techniques of this field of study can be used in the process of problem-solving as well. The present study intends to present a new and scientific algorithm for evaluation and selection of suppliers by combining multi attribute decision making techniques and improving their implementation process. For this purpose, similar studies were reviewed in the first step and then, assisted by organizational connoisseurs, 8 important and effective indices were extracted for the selection of suppliers: price, quality, good delivery, geographic location, payment terms, device technological capabilities, and after-sales services. In the second step using real data provided by YOUTAB Company, the suggested algorithm was explained. To this end, firstly, applying Entropy technique (completing decision matrix by Company's experts), initial weight of indices was extracted; then, with the help of AHP (conducting an opinion poll of the company's chief executive officer) a new weight for indices was obtained and then combined with initial weights so that the final weights could be calculate. Therefore, revised PROMETHEE technique was used to evaluate the four existing suppliers and analyze the results achieved.