Considerable investment in the installation of an automated manufacturing system requires scheduling approaches that highly utilize its resources. The incorporation of alternative operations into a scheduling system increases the utilization rate of resources and reduces the makespan of manufacturing products. In the paper, a heuristic algorithm is developed for a scheduling problem with and without alternative operations. The effect of alternative operations on the performance of schedules generated are studied with five dispatching rules. The testing effort involves 240 scheduling problems obtained for randomly generated data. The computational results show that the most dissimilar resources (MDR) dispatching rule for the case with alternative operations performs best among the dispatching rules tested. The quality of schedules (makespan, utilization rate of resources) generated with any dispatching rule improves when alternative operations are used.
