Circular blocking in flexible manufacturing systems: a matrix-based analysis

The problem of deadlock in a large class of re-entrant flowline systems is analysed. Based on a Petri net (PN) model, circular blocking is rigorously defined and shown to be equivalent to part-path deadlock. The analysis is performed in terms of circular waits. Coupling the PN marking transition equation with the matrix rule-based controller equation yields a dynamical system representation, a framework in which algorithms of polynomial complexity can be developed for computing the structures of deadlock analysis. This allows efficient dispatching with deadlock avoidance using a generalised kanban scheme