Design configuration for a mixed-model assembly system in case of low product demand

In order to accompany the increasing variety of costumers' demands, manufacturers tend to produce different models of the same product on an assembly line by introducing group assembly (GA) design concepts that improve the flexibility of assembly systems. Generally, when the demand for a set of similar products is relatively low and the set-up time is significant, the beneficial effects of the task repeatability of the straight line configuration are difficult to achieve. As a consequence, the fixed-point assembly philosophy is often preferred. This paper addresses the application of a mixed-model assembly balancing problem to an assembly-to-order environment in the case of low production rates and large number of tasks. The aim of this work is to propose an alternative design procedure for the balancing of semi-automated and mixed-model assembly systems under low product demand effects by the application of multi-turn circular transfers, such as a multi-stations rotating table. This layout configuration permits a job enlargement for human operators and, at the same time, provides an increment in task repeatability through the work-pieces assembling by increasing the number of the turns of the transfer. Finally, the developed heuristic procedure is tested on a simple rotating table assembly cell, a partial representation of a complete assembly system of domestic air compressors.