Case study based on a multi-period multi-criteria production planning model

The aim of the described model and procedures is to enable production planning by using multi-criteria linear programming in a manufacturing environment. It is assumed that linearity holds within acceptable tolerances and the problem of choice is present, i.e. the majority of products can be manufactured in a number of technically and financially different processes. The same resources, raw materials, machines, tools, and manpower can be assigned to different processes. The planning objectives include calculating the optimum production mix and achieving the capacity and material balance, while maximizing the contribution and minimizing the duration of the longest resource engagement. Multiple periods are applied to achieve approximated time scheduling. The described software also calculates the direct costs, enables easy locating of infeasibility cause and offers sensitivity analysis. A goal programming variation is introduced for maximum satisfaction of the market requirements. The described procedures are in practical use in a thermoplastics factory.