Petri nets and heuristic search for periodic scheduling

A method that uses a Petri net formulation and heuristic search is developed to handle periodic scheduling. This is an extension of a previous method for nonperiodic scheduling and treats both nonperiodic and periodic scheduling of flexible manufacturing systems with the same formulation. Periodic scheduling uses a more complex algorithm at the solution stage, which maintains the firing count vector for each marking and checks it against the T-invariant