Production flow control in a cell with groups of identical machines

This paper addresses the production control problems created in the schedul ing of a flexible manufacturing cell consisting of groups of identical mach ines. An actual manufacturing system, drawn from Sikorsky Aircraft Corporat ion, was used as a prototype for modeling the cell to study its optimal beh avior. The model, stated in the form of optimal production flow control com bines classical machine-part scheduling and scheduling of part fixtures. Su ch an extension induces three problem formulations comprising practical pro duction issues important for many modern plants other than Sikorsky. These formulations are related to three production cases covering different degre es of fixture availability. With the aid of the maximum principle, a numeri cal scheduling method is constructed for all three problem formulations, an d case studies are presented.