A progressive figure-based production planning system for a component manufacturer

This paper describes the results of a practical project where a production planning system for a component manufacturer was designed. The characteristics of the planning problem made the methods implemented in standard PPC systems unsuitable for this situation. For this reason a progressive figure-based system was designed. Progressive figures are the cumulative material flow at certain checkpoints (e.g., material input to a work center, planned delivery) plotted against time, which allows continuous modelling of the material flow and which therefore can handle arbitrary transfer and process patches for each operation. The progressive figure-based system described in this paper performs a time-phased loading to infinite capacity, separately for each product, and supports capacity planning based on Input/Output Control. This planning step is based on planned deliveries, but in many situations also on a detailed schedule for the first manufacturing step (raw parts manufacturing with large lot sizes). So we also consider the integration of detailed schedules into the progressive figure system. In this paper we describe the system in mathematical terms and also present an example. Furthermore, the basic ideas concerning the design process of the system, namely the reasons why this concept was chosen for the planning problem in question, are presented along with perspectives for future developments.