Many risk factors are dependent on each other and taking this into account can help manage appropriate decisions. The poor evaluation of these factors will impose high costs in many real applications, especially for a supply chain. There are different methods for risk evaluating and their effects for ranking them. For instant, in the fuzzy DEMATEL method, the experts’ linguistic opinions and preferences on the agent effects are used as the input. The important point is how these opinions are aggregated to produce the less computational error. In this regard, this paper proposes a new method based on statistical inferences for a fuzzy DEMATEL approach for evaluating the factors of a supply chain. This method was applied to a case study and the results showed that the proposed method was better than other methods for integrating the experts’ opinions in a supply chain. However, this method was proposed for the evaluation of supply chain factors, it can be applied to other systems as well.