Complexity Results for Flow-shop Scheduling Problems with Transportation Delays and a Single Robot

Abstract

The paper considers the problem of scheduling n jobs in a two-machine flow-shop to minimize the makespan. Between the completion of an operation and the beginning of the next operation of the same job, there is a time lag, which we refer to it as the transportation delays. All transportation delays have to be done by a single robot, which can perform at most one transportation at a time. New complexity results are derived for special case.