Change impact analysis for object-oriented programs

Small changes can have major and nonlocal effects in object-oriented languages, due to the use of subtyping and dynamic dispatch. This complicates life for maintenance programmers, who need to fix bugs or add enhancements to systems originally written by others. Change impact analysis provides feedback on the semantic impact of a set of program changes. This analysis can be used to determine the regression test drivers that are affected by a set of changes. Moreover, if a test fails, a subset of changes responsible for the failure can be identified, as well as a subset of changes that can be incorporated safely without affecting any test driver.