Load Forecasting, Priority Sequencing, and Simulation in a Job Shop Control System

This paper reports the development, installation and evaluation of a simulation which sequences shop operations for the next shift. Simulation outputs give each foreman the priority of jobs currently in his section and those jobs which might be coming through his area during the next work period. The foreman can determine in advance what tools, raw materials, etc., are needed and obtain them, thus tending to eliminate queue time for hot jobs. In three months of operation, the simulation has been more successful than initially expected. Coordination and expediting efforts have been reduced, in-process inventory has been reduced along with worker idle time, and schedule performance has improved. An additional important result noted during this time is an enlargement of the foreman's job. He has less need for coordinators and expediters since he has the information needed to make rational decisions on sequencing the work. This effort illustrates the practicality and desirability of incorporating advanced concepts into operating systems if the system's demands on working personnel are made compatible with the objectives and capabilities of the workers.