A Unified Test Case Prioritization Approach

Test case prioritization techniques attempt to re-order test cases in a manner that increases the rate at which faults are detected during regression testing. Coverage-based test case prioritization techniques typ-ically use one of two overall strategies, a total strategy or an additional strategy. These strategies prioritize test cases based on the total number of code (or code-related) elements covered per test case and the number of additional (not-yet-covered) code (or code-related) elements covered per test case, respectively. In this ar-ticle, we present a unified test case prioritization approach that encompasses both the total and additional strategies. Our unified test case prioritization approach includes two models (“basic ” and “extended”) by which a spectrum of test case prioritization techniques ranging from a purely total to a purely additional technique can be defined by specifying the value of a parameter referred to as the fp value. To evaluate our approach, we performed an empirical study on 28 Java objects and 40 C objects, considering the impact of three internal factors (model type, choice of fp value, and coverage type) and three external factors (cover-age granularity, test case granularity, and programming/testing paradigm), all of which can be manipulated by our approach. Our results demonstrate that a wide range of techniques derived from our basic and ex-tended models with uniform fp values can outperform purely total techniques, and are competitive with purely additional techniques. Considering the influence of each internal and external factor studied, th