Semiconductor manufacturing scheduling of jobs containing multiple orders on identical parallel machines

This paper investigates the identical parallel machine multiple orders per job (MOJ) scheduling problem to minimise total weighted order completion time, as motivated by 300 mm semiconductor manufacturing operations. Multiple orders per job scheduling is required when multiple customer orders are grouped together in one of a limited number of jobs for simultaneous processing - a challenge as customers measure order-level delivery performance, while manufacturers must schedule at the job level. We investigate two kinds of processing environments, serial and parallel processing, in the presence of non-zero order ready times and sequence-independent setup times between jobs. First, a mixed-integer program is proposed for the scheduling problem. As this problem is NP-Hard, a number of polynomial-time heuristic approaches are proposed. Experimental results identify appropriate heuristic techniques for analysing this practically motivated scheduling problem.