Understanding change requests to predict software impact

During its lifecycle, software experiences numerous changes that are either due to bug fixes or to the incorporation of new features. Implementing such changes is often more difficult than expected, which frequently leads to underestimation of the associated implementation effort. This paper describes work that aims to understand change impact based on the visualization of the characteristics of change requests using standard diagrams (e.g UML diagrams). Each diagram depicts different aspects of a software system and can illustrate factors that might drive the implementation effort. Using examples, in which we analyze three change requests, we describe how we determined the characteristics of the change requests. We furthermore discuss how the impact of change requests on diagrams relates to the implementation effort. Our overall goal is to develop a new impact analysis approach that helps determine software change impact based on the use of specific diagrams.