Identical machine scheduling problem with fuzzy due-dates

For most of scheduling problems, the due-dates of jobs are treated as fixed values, but that is not appropriate to all actual situations. In this paper, an identical machine scheduling problem with fuzzy due-dates is considered. Four properties are given by assuming that the due-dates to be fuzzy numbers. The problem of minimising the maximum completion time is proved to be NP-hard. The relationship between the scheduling results obtained by the ‘longest processing time’ algorithm and that of optimal algorithm is discussed.