Integrating Process Planning, WATC Weighted Scheduling, and WPPW Weighted Due-Date Assignment Using Pure and Hybrid Metaheuristics for Weighted Jobs

Abstract

Process planning, scheduling and due date assignment are three important manufacturing functions performed sequentially and separately. High interrelations between these functions forces us to consider integration. Here we studied integration of process planning, WATC scheduling and WPPW weighed due date assignment. At the literature due dates are assigned without taking into account of weights of each job but at this study we assigned closer due dates for more important customers. Thus we saved a lot at punishment function.  Conventionally only tardiness is punished but according to JIT approach we should penalize both earliness and tardiness. Since nobody desire long due dates, at this study we penalized all of weighted earliness, tardiness and due date related costs. We used genetic algorithm, hybrid-genetic algorithm, evolutionary strategies, hybrid-evolutionary strategies, random search and ordinary solutions as solution techniques and we observed the superiority of search algorithms over random search and especially over ordinary solutions. We step by step integrated these functions and higher integration level is found better. Although there are numerous works on IPPS and SWDDA problems, there are only a few works on IPPSDDA problem.