Scheduling availability of discrete event systems

Fault detection is a crucial and challenging task in the automatic control of complex systems, e.g. in flexible manufacturing systems (FMSpsilas) as a representative class of discrete event systems (DESpsilas). In this paper a discrete event system approach to the problem of failure diagnosis is presented. We propose a systematic procedure for detection of failure events using diagnoses implemented with stochastic coloured Petri nets (SCPN). An analytical approach for the availability evaluation of cellular manufacturing systems (as basic components of FMSpsilas) is presented, where a FMS is considered operational as long as its production capacity requirements are satisfied. The approach is used to evaluate transient and steady-state performance of alternative designs based on an industrial example. Possible extensions of the work are also discussed.