Deadlock avoidance in manufacturing systems with non-deterministic part routings

A deadlock avoidance algorithm for flexible manufacturing systems containing both multiple capacity resources and mixed choices in part routing is presented. The method determines whether moving a part to its next step is safe, unsafe, or undetermined. That classification is linear in complexity. Undetermined part movements are further analyzed using another procedure, which attempts to empty the system virtually to determine whether the move is safe or not. It is polynomial in complexity. An example is provided to illustrate how the method can be applied.