This document discusses the DEMATEL (Decision Making Trial and Evaluation Laboratory) method and its revised version. DEMATEL is used to analyze complex systems and determine the relationships between factors. The original DEMATEL assumes the total relationship matrix converges to zero, but this is not always true. The revised DEMATEL addresses this by introducing a small positive number to the normalization process, guaranteeing convergence. Steps for both methods and an example are provided to demonstrate the infeasibility of the original DEMATEL in some cases.