Robotic cell scheduling with operational flexibility

In this paper, we study the problem of two-machine, identical parts robotic cell scheduling with operational $exibility. We assume that every part to be processed has a number of operations to be completed in these two machines and both machines are capable of performing all of the operations. The decision to be made includes 8nding the optimal robot move cycle and the corresponding optimal allocation of operations to these two machines that jointly minimize the cycle time. We prove that with this de8nition of the problem 1-unit robot move cycles are no longer necessarily optimal and that according to the given parameters either one of the 1-unit robot move cycles or a 2-unit robot move cycle is optimal. The regions of optimality are presented. c © 2004 Elsevier B.V. All rights reserved.