Developing fuzzy expert system for supplier and subcontractor evaluation in construction industry

Increasing competition in the global market to gain customer satisfaction and maximize protability has been a challenge in the last decade for many construction corporations. In recent years, Supply Chain Management (SCM) has been introduced as one of the most eective approaches in the construction industry literature; further, the rst step in SCM implementation is supplier evaluation and thus nding and resolving its weaknesses. In this regard, this research identied the criteria for evaluation of two types of suppliers in the construction industry (rst, material and equipment suppliers named suppliers, and second, service suppliers named subcontractors) and their fuzzy membership functions, distinctly, through literature review, questionnaire survey, and statistical analysis of expert judgment. Since most of them are linguistic parameters, fuzzy approach through Mamdaniʹs inference mechanism has been utilized to develop a new methodology of fuzzy expert system. Thus, the developed expert system would evaluate and select the subcontractors and suppliers, distinctly, through three main criteria which are Quality, Cost, andWork relations history-timely delivery. The developed system was tested in three major companies and the results revealed signicant performance improvement of these construction companies.