Nowadays, companies have invested considerable resources in the implementation of Enterprise Resource Planning (ERP) systems. As a comprehensive software solution, ERP seeks to integrate all departments and functions of a company into a single computer system that can satisfy all departments' information needs. Many companies have wasted millions of dollars as a consequence of failed ERP implementation and adoption. Some of these failures come back to the selection of an ineffective ERP system. This article seeks to propose a method for selecting appropriate ERP systems, to enable firms' decision-makers to achieve an overall consensus by using a decision support process. In addition, since estimating distinct and precise data in the field of Information Systems is hard, a Fuzzy-Data Envelopment Analysis model is used to evaluate the value of each ERP software solution using subjective judgments made by a group of high prestigious IT experts in the petrochemical industry.