Simple Temporal Networks (STNs) provide a powerful and general tool for representing conjunctions of maximum delay constraints over ordered pairs of temporal variables. In this paper, we introduce Hyper Temporal Networks (HyTNs), a strict generalization of STNs, to overcome the limitation of considering only conjunctions of constraints but maintaining a practical efficiency in the consistency check of the instances. In a Hyper Temporal Network, a single temporal hyperarc constraint may be defined as a set of two or more maximum delay constraints which is satisfied when at least one of these delay constraints is satisfied. HyTNs are meant as a light generalization of STNs offering an interesting compromise. On one side, there exist practical pseudo-polynomial time algorithms for checking consistency and computing feasible schedules for HyTNs. On the other side, HyTNs offer a more powerful model accommodating natural constraints that cannot be expressed by STNs like “Trigger off exactly δ min before (after) the occurrence of the first (last) event in a set.”, which are used to represent synchronization events in some process-aware information systems/workflow models proposed in the literature.

Hyper Temporal Networks

COMIN, CARLO;POSENATO, Roberto;RIZZI, ROMEO
2017

Abstract

Simple Temporal Networks (STNs) provide a powerful and general tool for representing conjunctions of maximum delay constraints over ordered pairs of temporal variables. In this paper, we introduce Hyper Temporal Networks (HyTNs), a strict generalization of STNs, to overcome the limitation of considering only conjunctions of constraints but maintaining a practical efficiency in the consistency check of the instances. In a Hyper Temporal Network, a single temporal hyperarc constraint may be defined as a set of two or more maximum delay constraints which is satisfied when at least one of these delay constraints is satisfied. HyTNs are meant as a light generalization of STNs offering an interesting compromise. On one side, there exist practical pseudo-polynomial time algorithms for checking consistency and computing feasible schedules for HyTNs. On the other side, HyTNs offer a more powerful model accommodating natural constraints that cannot be expressed by STNs like “Trigger off exactly δ min before (after) the occurrence of the first (last) event in a set.”, which are used to represent synchronization events in some process-aware information systems/workflow models proposed in the literature.
Simple temporal networks, Temporal consistency, Hypergraphs, Pseudo-polynomial time algorithms, Mean-payoff games, Disjunctive temporal problems, Workflows
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11562/938199
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