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.