Flow shop scheduling with partial resource flexibility

Resource flexibility refers to the ability to dynamically reallocate units of resource from one stage of a production process to another in response to shifting bottlenecks. Recent research has demonstrated that substantial improvements in operational performance can be realized in both serial- and parallel-machine production environments through the effective utilization of resource flexibility. In these contexts the resource was assumed to exhibit complete flexibility. This research explores the extent to which the operational benefits associated with resource flexibility can be achieved in a flow shop environment using a partially flexible resource. Focusing on labor flexibility, we propose corresponding metrics for partial flexibility and formulate a model for flow shop scheduling with partial resource flexibility. On the basis of computational experiments, we explore properties pertaining to the relative amounts as well as the allocation of partial resource flexibility as it is distributed across the workforce. The conclusions drawn from this research provide significant insight into the management of flow shops with a workforce that is crosstrained to achieve partial flexibility. Moreover, we extend the principles developed by Jordan and Graves for partially flexible manufacturing plants to the flow shop scheduling environment, and we link these principles in a novel way to recent research on self-buffering flow lines.