Consistent reduction in discrete-event systems

In this paper we develop a general framework, called "consistent reduction", for formalizing and solving a class of state minimization/reduction problems in discrete-event systems. Given an arbitrary finite-state automaton and a cover on its state set, we propose a consistent reduction procedure that generates a reduced automaton, preserving certain special properties of the original automaton. The key concept of the consistent reduction procedure is the dynamically consistent cover; in each cell of this cover, any two states, as well as their future states reached by the same system trajectories, satisfy the binary relation induced from the given cover. We propose a new algorithm that computes a dynamically consistent cover that refines a given cover. We demonstrate the developed general framework on state reduction problems in different application areas. (C) 2022 Elsevier Ltd. All rights reserved.