Heuristic procedures and mathematical models for cell loading and scheduling in a shoe manufacturing company

This paper focuses on cell loading and scheduling issues in a shoe manufacturing company. It involves a three-phase solution methodology where first number of cells is determined, then cells are loaded and finally detailed scheduling is performed. Three different family definitions are used (subfamilies, families and superfamilies) during the cell loading process. Three cell loading heuristic procedures (H1, H2, and H3), a simple cell scheduling heuristic and two-level mathematical models are proposed and then compared with respect to makespan. An important observation is that better post-loading schedules did not lead to better post-scheduling results. As a result, the best schedule can only be known after both cell loading and cell scheduling functions are performed. The results showed that H1 led to the best post-scheduling makespan values and they were on the average within 3% of the optimal solution. The execution time for H1 was less than four seconds for the problems tested in the experimentation and this can be considered negligible for a manufacturing setting.