Optimal fair-load scheduling-a case study of a molding factory

In view of the growing mold and die industry, and due to the fact that most current manufacturers utilize 24-hour operations, there is a need to automate the scheduling and assignment of mold and die work-shifts. Manual scheduling and assignment are time-consuming and pose problems to corporate departments. Decisions-makers often spend a great amount of time on communications and work-shift arrangements, while the outcome of the final work-shift may still be non-optimal. In this research, the actual demands and standard of fairness are factors considered for the scheduling and assignment of the process-personnel of a molding factory. The demands on work-shifts during daytime and nighttime in a fixed weekly period are considered. A Binary Integer Programming (BIP) approach is taken for the formulation of the problem. The test results using the real data from a molding factory show that the optimal work assignment with fair loading out performs the manual approach for higher efficiency and fairness. By using the BIP approach, there is a 21.04% reduction in numbers of assignment and a 97.44% reduction in deriving a solution.