Cost-sensitive precomputation of real-time-aware reconfiguration strategies based on stochastic priced timed games

In many recent application domains, software systems must repeatedly reconfigure themselves at runtime to satisfy changing contextual requirements. To decide which next configuration is presumably best suited is a very challenging task as it involves not only functional requirements but also non-functional properties (NFP). NFP include multiple, potentially contradicting, criteria like real-time constraints and cost measures like energy consumption. Effectiveness of context-aware reconfiguration decisions further depends on mostly uncertain future contexts which makes greedy one-step decision heuristics potentially misleading. Moreover, the computational runtime overhead for reconfiguration planning should not nullify the benefits. Nevertheless, entirely pre-planning reconfiguration decisions during design time is also not feasible due to missing knowledge about runtime contexts. In this article, we propose a model-based technique for precomputing context-aware reconfiguration decisions under partially uncertain real-time constraints and cost measures. We employ a game-theoretic approach based on stochastic priced timed game automata as reconfiguration model. This formal model allows us to automatically synthesize winning strategies for the first player (the system) which efficiently delivers presumably best-fitting reconfiguration decisions as reactions to moves of the second player (the context) at runtime. Our tool implementation copes with the high computational complexity of strategy synthesis by utilizing the statistical model checker Uppaal Stratego to approximate near-optimal solutions. We applied our tool to a real-world example consisting of a reconfigurable robot support system for the construction of aircraft fuselages. Our evaluation results show that Uppaal Stratego is indeed able to precompute effective reconfiguration strategies within a reasonable amount of time

Reconfiguration management in manufacturing: A systematic literature review

International audienceAufgrund kürzerer Innovations- und Produktlebenszyklen sowie wirtschaftlicher Volatilität steigt der Rekonfigurationsbedarf von Produktionssystemen. Daher wird im Rahmen dieser Arbeit eine systematische Literaturrecherche zum Rekonfigurationsmanagement in der Produktion durchgeführt, um zu ermitteln, inwieweit dies in der Literatur adressiert wird. Dazu wird zunächst eine Definition des Rekonfigurationsmanagements gegeben und zentrale Aspekte rekonfigurierbarer Fertigungssysteme sowie die Defizite der heutigen Rekonfiguration von Fertigungssystemen dargestellt. Aus diesen werden die Anforderungen zur Beantwortung der formulierten Forschungsfrage abgeleitet. Anschließend wird das methodische Vorgehen der Literaturrecherche skizziert, welches auf der Bewertung der abgeleiteten Anforderungen basiert. Abschließend werden die erzielten Ergebnisse dargestellt und weitergehende Erkenntnisse erläutert.Driven by shorter innovation and product life cycles as well as economic volatility, the demand for reconfiguration of production systems is increasing. Thus, a systematic literature review on reconfiguration management in manufacturing is conducted within this work in order to determine by which degree this is addressed by the literature. To approach this, a definition of reconfiguration management is provided and key aspects of reconfigurable manufacturing systems as well as shortcomings of today’s manufacturing systems reconfiguration are depicted. These provide the basis to derive the requirements for answering the formulated research question. Consequently, the methodical procedure of the literature review is outlined, which is based on the assessment of the derived requirements. Finally, the obtained results are provided and noteworthy insights are given