Today, Iranian employers and contractors using the EPC method in several large and small projects, need to analyze previous experiences to correct the problems of this method and develop it in future projects. In this research, first, by identifying the common lawsuits between the group of consulting engineers and contractors in the country's construction projects and ranking the existing lawsuits, it analyzes and examines it so that it can provide solutions for reforming the country's technical executive system by carefully examining the influential factors. The indicators obtained through library studies and face-to-face interviews with experts will be identified in the form of 4 general categories (level one) and 24 sub-indicators (level 2), after collecting information about all options. According to the determined indicators, in order to evaluate and select the most preferred index by the relevant subgroups and prioritize them, decision criteria with multiple indicators have been used. In this research, using AHP method, the indicators presented in this topic have been identified and then prioritized and weighted. The criterion of non-fulfillment of contractual obligations of employer and consultant with weight (0.523) is the most important criterion in analyzing and reviewing claims. Common among us consultants and. Contractors in EPC contracts are construction projects and the wrong factors in the tender documents with weight (0.089) are the least important criteria among the 4 main criteria available.