AN ANALYTICAL PERFORMANCE-MODEL FOR ASSEMBLY SYSTEMS WITH AUTOMATIC INSPECTION STATIONS AND REPAIR LOOPS

Automatic Assembly Systems (AASs) form an important class of manufacturing systems. Due to the difficulty of modeling them via simulation, some analytical tools have been developed for the performance evaluation of such systems. Modeling of a certain class of AASs that have test stations and counter-flow repair loops deserves special attention. Incorporating a counter-flow secondary loop in the material handling system in addition to the main loop brings the phenomena of splitting and merging of the flow of assemblies which make the analytical model more intricate. In this paper, a closed system version of Whitt's second order approximations for GI/G/1 queues is applied to AASs with repair loops as an analytical tool for performance evaluation. The results of the analytical model are compared with those of simulation. The analytical method yields approximate but fast results and appears to be a promising technique for the initial performance evaluation of AASs with repair loops. © 1990.