A Change Impact Model Encompassing Ripple Effect and Regression Testing

Maintenance is one of the major concerns of software developers and industries. The success of this critical phase depends highly on the changeability of the software. In order to evaluate the flexibility of a software to accommodate changes, we have defined a change impact model for object-oriented systems. As previously defined, it calculates the impacted classes due to an atomic change. In this paper we present an extension of the change impact model to obtain a fine-grained assessment of system changeability. As a first extension, we take into account the classes that are impacted by ripple effect. In a second extension, we also count classes that need to be re-tested even if they are not directly affected. An experimentation is planned to study the relationship between software’s changeability assessed by the extended change impact model and design properties.