On a two-stage hierarchical production planning system for process industries

The objective of this paper is to propose a relevant production planning procedure for multi-item continuous production by the specified petrochemical plant, which is one of the typical processes of petrochemical companies. The tough problem of such production system management is to determine the product-mix to be produced in the current planning period based on termwise forecasts of demand quantities, constraints of plant capability, etc. Most of the current procedures operated in actual factories are empirical heuristic approach and were relevant under stable demand structure. However, due to their rough structure and recent versatile market needs, inefficient utilisation of plant and growing indirect resources consumption for production activity such as man-power of management become urgent problems. From this point of view, a systematic procedure to eliminate such difficulties is proposed in terms of a two-stage automated hierarchical planning procedure, consisting of both a coordination function between production periods and an efficient job lot sequencing function. Then, the feasibility and relevance of the system are investigated through quantitative simulation experiments for further consideration of actual implementation.