On the Round Trip Path Testing Strategy

A number of techniques have been proposed for state-based testing. One well-known technique (criterion) is to traverse the graph representing the state machine and generate a so-called transition tree, in an attempt to exercise round trip paths, i.e., paths that start and end in the same state without any other repeating state. Several hypotheses are made when one uses this criterion: exercising paths in the tree, which do not always trigger complete round trip paths, is equivalent to covering round-trip paths; different traversal algorithms are equivalent. In this paper we investigate whether these assumptions hold in practice, and if they do not, we investigate their consequences. Results also lead us to propose a new transition tree construction algorithm that results in higher efficiency and lower cost.