Integrating safety in manufacturing systems

An integrated safety and manufacturing system (ISM) was developed. With this ISM system, a communication method between the safety system and the manufacturing system by means of a hybrid control strategy was introduced. The hybrid control strategy combined the hierarchical and heterarchical control in order to take advantage of both. Thus, a safety system can have the same weight as that of a manufacturing system, and is no longer an auxiliary part of a system. The safety approach, which was proposed for developing the safety system in ISM system. started by applying open‐loop safety controls and closed‐loop safety controls to machines. Applying a safety training program and personal protection equipment to humans followed. Then, a user‐coded safety module was developed for users who want to integrate the safety concept into their simulation system. Finally, a simulated application example illustrated the compatibility of the safety module and the differences of a system cell before and after integration with the safety system. The simulation results, from throughput, utilization, and safety aspects, are discussed. @ 1995 John Wiley & Sons, Inc.