Abstract

Since exhaustive testing is in general impossible, an important step in the testing process is the development of a carefully selected test suite. Selection of test cases is not a trivial task. We propose to base the selection process on a well{dened strategy. For this purpose, we formulate two heuristic principles: the reduction heuristic and the cycling heuristic. The rst assumes that few outgoing transitions of certain states show essentially dierent behaviour. The second assumes that the probability to detect erroneous behaviour in a loop decreases after each correct execution of the loop behaviour. We formalize these heuristic principles and we dene a coverage function which serves as a measure for the error{detecting capability of a test suite. For this purpose we introduce the notion of a marked trace and a distance function on such marked traces. Keywords: test selection, test coverage, trace distance, test selection heuristics, edit distance. 1

Citations