Abstract:

When new functionalities (features) are added to a telephone system, it may be the case that the new features prevent preexisting features from exhibiting their behaviour in the new context, Such design flaws, if not detected at the specification level, may have disastrous consequences once the system is implemented. We present some features for detecting these flaws at the design stage. A telephone system, with its features, is modeled as a collection of communicating oricesses, using LOTOS. In a first approach, LOTOS testing theory is used to detect feature interactions, which show up as deadlocks with appropriately chosen testing processes. In a second approach, feature interactions show up as ambiguities, i.e., cases of non-determinism, which can be detected by a process of backward execution.