A system built around Material Requirements Planning, also including the additional planning functions of Production Planning, Master Production Scheduling, and Capacity Requirements Planning. Further, once the planning phase is complete and the plans have been accepted as realistic and attainable, the execution functions come into play. These include the shop floor control functions of Input-Output measurement, Dispatching, plus Anticipated Delay Reports from both the shop and vendors, Vendor Scheduling, etc. The term “closed-loop” implies that not only is each of these elements included in the overall system but, also, that there is feedback from the execution functions so that the planning can be kept valid at all times.