Performance evaluation of family-based dispatching in small manufacturing cells

In many practical instances, the choice of whether to apply family-based dispatching or not can be decided per machine. The present paper explores the impact of the location of family-based dispatching, load variations between machines and routing of jobs on the flow time effect of family-based dispatching. These factors are explored in small manufacturing cells with and without labour constraints. An industrial case motivates the study. A simulation study is performed to assess the impact of these effects. The results show that shop-floor characteristics such as routing and load variation impact the decision where to locate family-based dispatching in manufacturing cells without labour constraints. By contrast, the effect of family-based dispatching is much less vulnerable to shop-floor characteristics in cells with labour constraints. Since workers are the bottleneck in these cells, it becomes less important at what machine the set-up time involving a worker is reduced. In general, there seems to be a trade-off between the positive effect of applying family-based dispatching at a (bottleneck) machine and the possible negative effect of the more irregular job arrivals at subsequent machines. The results further indicate that family-based dispatching is more advantageous in cells with labour constraints than in cells without labour constraints, when both types of manufacturing cells have comparable machine utilizations.