Further Studies on Timed Testing of Concurrent Systems
- The setting of 'Timed Testing of Concurrent Systems' (Vogler 1995) is extended in three aspects: i) semantic equivalences are replaced by preorders, yielding implementation-specification-relations, ii) discrete time is generalized to continuous time and iii) the three variants of timed behaviour (liberal, mixed and strict) are completed by the 'dual' of mixed behaviour. As main results we derive: i) if a strictly timed system performs in both best- and worst-case as well as another strictly timed one, then both systems must be equivalent; ii) considering the basic-semantics, continuous time is in general more discriminating than discrete time, but never in tests; iii) the 'dual' of mixed behaviour cannot be related to some classical notion of concurrent behaviour in an equivalent way as it is possible for the original three variants.