Hierarchical interface-based non-blocking verification

Int. J. Found. Comput. Sci.

Streader

Reeves

2006

This paper studies conflicts from a process-algebraic point of view and shows how they are related to the testing theory of fair testing. Conflicts have been introduced in the context of discrete event systems, where two concurrent systems are said to be in conflict if they can get trapped in a situation where they are waiting or running endlessly, forever unable to complete their common task. In order to analyse complex discrete event systems, conflict-preserving notions of refinement and equivalence are needed. This paper characterises an appropriate refinement, called the conflict preorder, and provides a denotational semantics for it. Its relationship to other known process preorders is explored, and it is shown to generalise the fair testing preorder in processalgebra for reasoning about conflicts in discrete event systems.

Section: ⇒mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Conflicts and Fair Testing

Int. J. Found. Comput. Sci.

Streader

Reeves

2006

“…Structural (Leduc et al, 2000;Lee and Wong, 2002) and prioritybased (Wong et al, 2000) approaches have been suggested. These techniques give some insight how systems can be designed to be free from conflict, but they rely on design carried out by users, and therefore cannot be performed automatically.…”

Section: Introductionmentioning

confidence: 99%

“…A common way of fighting state explosion is to exploit modular system structures (Leduc et al, 2000;Wong and Wonham, 1998). Often it suffices to analyse only subsystems of a large system to establish that the entire system satisfies a property of interest (Åkesson et al, 2002;Brandin et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

On the set of certain conflicts of a given language

IFAC Proceedings Volumes

2004

Two concurrent processes are said to be in conflict if they can get trapped in a situation where they both are waiting or running endlessly, forever unable to complete their common task. In the design of reactive systems, this is a common fault which can be very subtle and hard to detect. This paper studies conflicts in more detail and characterises the most general set of behaviours of a process which certainly leads to a conflict when accepted by another process running in parallel. It shows how this set of certain conflicts can be used to simplify the automatic detection of conflicts and thus the verification of reactive systems.

“…Several approaches to modular synthesis of discrete event systems have been suggested in the literature [4], [5], but so far most of them rely on structure to be provided by users and hence are hard to automate. Those that can be automated [6]- [9] either do not consider nonblocking, or are guaranteed to produce a least restrictive supervisor only under certain constraints.…”

Section: Introductionmentioning

confidence: 99%

Supervision Equivalence

Flordal

2006 8th International Workshop on Discrete Event Systems

Abstract-This paper presents a general framework for modular synthesis of supervisors for discrete event systems. The approach is based on compositional minimisation, using concepts of process equivalence. Its result is a compact representation of a least restrictive supervisor that ensures controllability and nonblocking. The method is demonstrated to reduce the number of states to be constructed for a simple manufacturing example, and the framework is proven to be sound.