CAUSES AND SAFELY EFFECTS OF PRODUCTION DISTURBANCES IN FMS INSTALLATIONS - A COMPARISON OF FIELD SURVEY STUDIES IN THE USA AND FINLAND

Installation and operation of flexible manufacturing systems (FMSs) re quires a relatively large investment of capital. Therefore, high utili zation of manufacturing capacity and low downtime due to system distur bances are of great importance. In addition to productivity and qualit y, the production disturbances have an effect on the safety of the per sonnel involved in operating and maintaining the FMS installations. Th e aims of this study were: (1) to determine the causes of production d isturbances and their effects on the operation and safety performance of the FMS installations, (2) to analyze and compare disturbance data for the FMS installations in the U.S. and Finland, and (3) to identify ways to improve safety and efficiency in FMS implementations. The sur vey included 14 FMS installations in the U.S. and 31 FMS installations in Finland. The field survey questionnaire included six sections: (1) background information, (2) planning, (3) performance, (4) organizati on, (5) training, and (6) production disturbance situations. The analy sis of system disturbances was based on the data about 35 disturbances reported in the FMS installations in the U.S. and 52 FMS-related dist urbances in Finland. About 12% of all the disturbances observed in the U.S. and 35% of the disturbances in Finland caused hazardous situatio ns or accidents. The FMS disturbances were classified into design erro rs, component failures, human errors, and external factors. More than one-third (34%) of the disturbances in the U.S. and in Finland (35%) w ere mainly caused by system design-based errors or flaws. The study re sults illustrate the scope of safety problems experienced in the imple mentation and use of flexible manufacturing systems, and provide new f ield data that are not systematically collected and classified today. (C) 1996 John Wiley & Sons, Inc.