Compositional nonblocking verification with always enabled events and selfloop-only events

This paper proposes to improve compositional nonblocking verification through the use of always enabled and selfloop-only events. Compositional verification involves abstraction to simplify parts of a system during verification. Normally, this abstraction is based on the set of events not used in the remainder of the system, i.e., in the part of the system not being simplified. Here, it is proposed to exploit more knowledge about the system and abstract events even though they are used in the remainder of the system. Abstraction rules from previous work are generalised, and experimental results demonstrate the applicability of the resulting algorithm to verify several industrial-scale discrete event system models, while achieving better state-space reduction than before

Coalgebra, Concurrency, and Control

Coalgebra is used to generalize notions and techniques from concurrency theory, in order to apply them to problems concerning the supervisory control of discrete event systems. The main ingredients of this approach are the characterization of controllability in terms of (a variant of) the notion of bisimulation, and the observation that the family of (partial) languages carries a final coalgebra structure. This allows for a pervasive use of coinductive definition and proof principles, leading to a conceptual unification and simplification and, in a number of cases, to more general and more efficient algorithms

The impact of requirement splitting on the efficiency of supervisory control synthesis

Supervisory control theory provides means to synthesize supervisors for a cyber-physical system based on models of the uncontrolled system components and models of the control requirements. Although several synthesis procedures have been proposed and automated, obtaining correct and useful models of industrial-size applications that are needed as their input remains a challenge. We show that the efficiency of supervisor synthesis techniques tends to increase significantly if a single large requirement is split into a set of smaller requirements. A theoretical underpinning is provided for showing the strength of this modeling guideline. Moreover, several examples from the literature as well as some real-life case studies are included for illustration