Abstract

This invention is a look-ahead method for determining optimum production schedules for each production step based on factory-wide monitoring of in-process part queues at all potential production bottlenecks. For each product having associated therewith a throughput bottleneck, a maximum queue quantity QMAX and a minimum queue QMIN quantity are assigned. When a machine completes a lot of a particular product at a production step P that proceeds the bottleneck step B, the look-ahead method is initiated. The queue at step P is searched and the next lot to be processed is selected. If that lot is a product for which QMAX and QMIN values have been assigned at step B, then the queue quantity at step B is determined. If, on one hand, the queue quantity at step B is less than QMAX, or between QMAX and QMIN and the queue quantity is climbing upward from a sub-QMIN value and has not yet exceeded its QMAX value, then the lot is processed without further analysis. If, on the other hand, the queue quantity at step B is greater than QMAX , or between QMAX and QMIN and the queue quantity is descending from a quantity greater than its QMAX and has not yet fallen below its QMIN value, then that product has a set flag status associated therewith, and the lot will not be processed until after all other lots which have a clear flag status are processed.