Abstract
This paper discusses optimal flexible cyclic scheduling for a two-machine robotic cell with finite buffer for WIP's (work-in-process) such as FMC's (flexible manufacturing cells), where jobs are processed on two machines in the same order, and sent between machines by a transportation robot. Each cycle is allowed to have different types of jobs, and the objective is to find an optimal schedule that minimizes the cycle times. In this paper we propose a heuristic algorithm based on Gilmore-Gomory and Johnson methods for this problem, and show by numerical experiments that it gives good approximate schedules of about 2% or less relative errors for any size of buffer capacity in short computational time. Also, we numerically show how the system parameters affect the system efficiency, and conclude that one of the effective ways for improving the efficiency is to reduce the diversity of job processing times rather than to have large buffer and a fast transportation robot.
