1997 Volume 9 Issue 6 Pages 995-1004
In this paper, we show how non-fuzzy scheduling problems can be reformulated in the framework of fuzzy due-data.The membership function of a fuzzy due-data assigned to each job shows the human user's satisfaction grade for the completion time of that job. Thus the fuzzy due-data is directly related to the eariliness and tardiness penalty in conventional scheduling problems. The fuzzy due-data can be also used for representing other scheduling criteria such as the makespan and the total flowtime. In this paper, we first desribe the concept of fuzzy due-date. Next we show that various scheduling criteria can be represented in terms of the membership function of the fuzzy due-data assigend to each job. That is, we show that many non-fuzzy scheduling problems can be reformulated through the concept of fuzzy due-date. Then we show how we can combine various scheduling criteria into a single measure using various shapes of membership functions for fuzzy due-date. The similarity and the difference between conventional scheduling problems and fuzzy scheduling problems are illustrated by computer simulations on several numerical examples.
