A study on production planning for products with restricted demand periods

This paper deals with problem of determining the number of set-ups, production lot size, production priority and production starting time under a single stage lot production system. The product items produced in the system have different demand periods and starting time for demand. The production planning aims to determine the number of set-ups for load ratio, set-up time ratio and maintain each demand point for item. As a result of analysis, a structural formulation of product inventory is revealed. It can clarify the relation among the number of set-ups each product, production lot size of each product, required quantity of each product, starting time for demand of each product, processing time and set-up time of each product, each demand period, product inventory. Based on the formulation, an algorithm is proposed to determine the number of set-ups for load ratio and set-up time ratio, production lot sizes and production priority.