When modeling concurrent or cyber-physical systems, non-functional requirements such as time are important to consider. In order to improve the timing aspects of a model, it is necessary to have some notion of what it means for a process to be faster than another, which can guide the stepwise refinement of the model. To this end we study a faster-than relation for semi-Markov decision processes and compare it to standard notions for relating systems. We consider the compositional aspects of this relation, and show that the faster-than relation is not a precongruence with respect to parallel composition, hence giving rise to so-called parallel timing anomalies. We take the first steps toward understanding this problem by identifying decidable conditions sufficient to avoid parallel timing anomalies in the absence of non-determinism.
|Tidsskrift||Electronic Proceedings in Theoretical Computer Science, EPTCS|
|Status||Udgivet - 20 jan. 2020|
|Begivenhed||16th Workshop on Quantitative Aspects of Programming Languages and Systems, QAPL 2019 - Prague, Tjekkiet|
Varighed: 7 apr. 2019 → …
|Konference||16th Workshop on Quantitative Aspects of Programming Languages and Systems, QAPL 2019|
|Periode||07/04/2019 → …|