The "enterprise resource planning" (ERP) and business process integration through organizations have many benefits, including increased productivity, improved quality and lower costs. However, ERP implementations are complex and expensive and the processes of ERP implementation projects often fail. In this research, the most influential elements, verified by appropriate publications and discussions with the experts, in breaking down of ERP systems has been categorized in four groups of: managerial, human resources, processing and technological factors. To determine the level of importance of each element and ranking of statistical companies, based on their readiness in implementing a successful ERP, some questionnairs were handed out. The identified elements, found by the experts, were evaluated through Shanon entropy technique to assess their degree of significance. According to the weight of every element, we ranked companies through TOPSIS technique (Excel software) and linear assignment (Lingo software and answers like Global optimal). Because of the incompatibility of some results of these two techniques, we used the combinatory mean arithmetic to reach unanimous consent. The results showed that the companies which were ready to implement ERP successfully were specifically fulfilled by their managerial and human resource preparedness.