Logistics planning optimizing the minimum amount of material which have to be placed in multi-item multi-echelon supply chain depots by dynamic programming

In the competitive environment of nowadays world, it is known that companies can not survive solely by producing quality goods. Thus, logistics activities have become a focus of interest for companies. Companies can raise their incomes not only by selling their products but also by planning and executing logistics activities, pursuing and reporting activities, and meeting customer requirements depending on quality and quantity demands.Since logistics is extremely important for companies, all of the activities which will occur in strategic, tactic and operational levels must be planned in full detail and the optimization must be preformed by means of mathematical methods while making decisions. Inventory management is an important issue to meet customer requirements on time with minimum logistics costs.In recent years, new improvements have been taking place in inventory management area. From the origin source of a raw material to the final consumption point because of the need for material stocking and extending distribution networks, the concept of multi echelon inventory system which decreases the inventory amount by %20-30 has been developed and applications become prevalent. Since dynamic programming enhances to solve the problems with ease by decomposing big problems, which can be hard to solve, into smaller sub problems, it is used in optimization of multi echelon inventory systems.In the first chapter of this study, some necessary information about the description and the scope of logistics is presented. In the second chapter, the realization of logistic planning, logistic network design, multi echelon inventory systems, logistic decision support systems, and dynamic programming method are defined. In the last chapter, order inventory plan of three different items with certain demand levels in a period of three days is analyzed in a multi echelon inventory systems approach including nine retailers, one central and three regional warehouses using the dynamic programming method.Keywords: Logistics, Planning, Network Design, Multi-Item Multi-Echelon Inventory, Decision Support, Dynamic Programming