Preventing second level and avoiding first level deadlocks in FMS

We build a discrete-event model of concurrent FMS processes and consider the problem of its safe and maximally flexible behavior. To reduce the complexity of the problem we bound the class of systems addressed by the model with the requirement that the capacity of some selected resources be greater than one. The constraint prevents the occurrence the second level deadlocks while the first level deadlocks are avoided by the means of a computationally easy, maximally permissive, real-time test. The correctness of the method is formally proved.