Software quality management, which leads to improve the performance capability of project, has been studied on the many viewpoints. It is hard work to compare the each process level assessed with CMM, SPICE and Six-Sigma, which are the popular techniques for the industry of software and system management. This paper discusses the relationship between the three process assessments and the derivation of overall mapping table which relates the result levels assessed with SPICE, CMM and Six-Sigma. Additionally, we analyze the mapping-effectiveness, which is the most effectual way after mapping of the levels or before, using the Analytic Hierarchy Process method.