Adequate process modeling is one of the key factors for the success of software organizations. Currently, organizations face with a very high competition and consequently they have to continuously improve their processes. This improvement could require changes of the process models so it is important to evaluate the maintainability of these models to facilitate their evolution. In this paper we present the results obtained with the replication of an experiment to validate a set of metrics for Software Process Models (SPMs). The replicas were performed at the Italian Universities of Sannio (Italy) and Federico II (Naples). They are part of a family of experiments and have confirmed the results obtained in the original experiment carried out at the University of Castilla-La Mancha (Spain). As a result a set of useful indicators of the understandability and modifiability of the SPMs, which are two key sub-characteristics of their maintainability, have been obtained.