Scheduling Parallel Manufacturing Cells with Resource Flexibility

This paper investigates the improvements in manufacturing performance that can be realized by broadening the scope of the production scheduling function to include both job sequencing and processing-time control through the deployment of a flexible resource. We consider an environment in which a set of jobs must be scheduled over a set of parallel manufacturing cells, each consisting of a single machine, where the processing time of each job depends on the amount of resource allocated to the associated cell. Two versions of the problem are introduced: a static problem in which a single resource-allocation decision is made and maintained throughout the production horizon, and a dynamic problem in which resource can be reassigned among the production cells as local bottlenecks shift. We provide mathematical formulations for each version of the problem, establish problem complexity, identify important characteristics of optimal solutions, develop optimal and heuristic solution approaches, and report the results of a set of computational experiments. The computational results demonstrate that substantial improvements in operational performance can be achieved through effective utilization of resource flexibility.