2 Citations (Scopus)
60 Downloads (Pure)


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.

Original languageEnglish
JournalElectronic Proceedings in Theoretical Computer Science, EPTCS
Pages (from-to)29-42
Number of pages14
Publication statusPublished - 20 Jan 2020
Event16th Workshop on Quantitative Aspects of Programming Languages and Systems, QAPL 2019 - Prague, Czech Republic
Duration: 7 Apr 2019 → …


Conference16th Workshop on Quantitative Aspects of Programming Languages and Systems, QAPL 2019
Country/TerritoryCzech Republic
Period07/04/2019 → …

Bibliographical note

Funding Information:
Acknowledgements. Mathias R. Pedersen was supported by the ASAP project (no. 4181-00360) funded by the Danish Council for Independent Research. Kim G. Larsen was supported by the ERC Advanced Grant LASSO (no. 867096).

Publisher Copyright:
© M.R. Pedersen, G. Bacci, & K.G. Larsen.

Copyright 2020 Elsevier B.V., All rights reserved.


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