Multi-level inventory matching and order planning for steel plants based MTO-MTS

This paper proposes an optimization model of multi-inventory matching and order planning of the iron-steel factories based on the mixed strategy of MTO-MTS. The model considers the multiple objectives, i.e., the total cost of earliness/tardiness penalty, tardiness penalty in delivery time window, production penalty; inventory matching, order cancellation penalty and machine capacity penalty. An improved PSO algorithm is designed along with the strategy of the initial feasible solution´s construction and repair of infeasible solutions. In the computational experiments, parameters of PSO are also analyzed. Three sets of real data from a steel manufacturing company are used to perform computational experiments for PSO, local search, and improved PSO. Numerical results show the validity of the model and efficacy of the improved PSO method.