Nowadays, there are several software process models, which fulfill different purposes, approaches and requirements. However, this proliferation causes some confusion in the industry about the benefits or advantages of each proposal. In this context, studies have been conducted to determine the existing equivalence or the extent of coverage between these models having used different approaches to the comparisons. This work aims to present a study of techniques and experiences on comparison of software process models. For this study, a systematic literature review was conducted in relevant databases and available documents finding that there are few works or experiences in this area and it represents an aspect in software engineering the requires a higher level of research and development. Five different methods to compare process models were found and it was identified that the CCT - Comparison Composition Tree method is the unique that have a graphic representation.