Applying the Simple Fixed Rate Approach to Solve the Economic Lot Scheduling Problem with Shelf Life under the Basic Period Approach

• Main Authors: Yu-Wei Kuo, 郭育瑋
• Other Authors: Yu-Jen Chang
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/89906284400862704571

碩士 === 東海大學 === 資訊管理學系 === 102 === The economic lot scheduling problem (ELSP) is concerned with the scheduling of cyclical production of products on a single facility in equal lots over an infinite planning horizon. The objective of the ELSP is to determine the lot size and the schedule of production of each product so as to minimize the total cost incurred per unit time and generate a reasonable and feasible production schedule. In order to consider more realistic production constraints, many researchers discussed many kinds of different production situations. Some researchers indicated that many industries must strictly consider shelf life for all products. When a product is stored over its shelf life, this product cannot be used or sold. Therefore, a production system must consider the shelf life constraint for all products during generating a feasible production schedule in order to avoid the loss of profits. Several researchers indicate that applying the fixed rate approach can reduce its holding cost in order to lower the average total cost. This approach also can extend the expiration date of shelf life for a product. As a result, this research applies the fixed rate approach to change the production rate of a product to solve the economic lot scheduling problem with considering shelf life under the basic period approach. The key of this research is how to find the cyclic multipliers {ki} of all products. The cyclic multiplier ki constrain that a product must be produced for every ki basic periods. So, this research uses the Particle Swarm Optimization to find the optimal or near-optimal cyclic multipliers {ki} of all products in order to obtain an optimal solution with the lowest average total cost. Our numeral experiments show that our approach is more efficient to find better solution than the traditional basic period solving approach for the ELSP. Our mathematic model for applying the fixed rate approach to solving the ELSP under the basis period approach can be a reference for other related researches.