A HETERARCHICAL GENERIC DISCRETE MANUFACTURING SIMULATION-MODEL AND ITS APPLICATION IN A WORLD-CLASS MANUFACTURING ENVIRONMENT

Current factory design and evaluation is very primitive. Factory components are designed in many cases independently. Product and process design are not well integrated. An encompassing framework is needed for iterating through a series of total factory designs, searching for optimal performance. In addition, a vehicle is needed for predicting the performance of a proposed advanced manufacturing system, so that engineers may have a sound means for evaluating such proposals. A heterarchical discrete manufacturing SIMNET II simulation model (SIMCELLS) was developed as a comprehensive methodology for designing and evaluating discrete manufacturing systems. SIMCELLS allows manufacturing systems engineers to experiment with alternative system structures and control strategies while seeking that combination of design features that will produce the desired overall system performance. The model in combination with a modernization programme is enabling a firm to successfully manufacture and sell trucks meeting international standards. The SIMNET II model (SIMCELLS) simulates the entire fabrication process monitoring the load of over 100 machines and following the work-in-process of over 1900 parts. It works under push or pull control environments and predicts daily production accurately. It permits the testing of manufacturing configurations and is being used to design a new plant based on group technology and cell concepts. The company has increased production by 260%, reduced fixed total costs by 26%, and increased net profits by 70% within 18 months.