the planning of production and control of inventory problem is one of most important problems that companies are face with them. some times inattention to uncertainty in these problems causes to increase of costs of inventory control systems. one of the important ways encountering to uncertainty is the widespread of fuzzy sets instead of crisp numbers because in this approach, we can determine ...

generally ordering policies are done by two methods, including fix order quantity (foq) and fix order period (fop). these methods are static and either the quantity of ordering or the procedure of ordering is fixing in throughout time horizon. in real environments, demand is varying in any period and may be considered as uncertainty. when demand is variable in any period, the traditional and st...

in this paper, a supplier-retailer transportation system is investigated as a two-echelon environment. there is a single location in each echelon; the unique supplier at the first echelon has to replenish the retailer's warehouse at the second echelon. by the way, the shortage situation should be avoided. for this situation, a model is provided based on the traditional eoq model. the inven...

Changes in wholesale supply operations at the Veterans Administration could reduce net ordering and carrying costs, inventory investment, and warehouse space. The primat-y vehicle for achieving these reductions is the economic order quantity principle--a mathematical method for determining the purchase quantity that will result in the lowest total cost to order and carry inventory. Additional r...

Generally ordering policies are done by two methods, including fix order quantity (FOQ) and fix order period (FOP). These methods are static and either the quantity of ordering or the procedure of ordering is fixing in throughout time horizon. In real environments, demand is varying in any period and may be considered as uncertainty. When demand is variable in any period, the traditional and st...

In this paper, a supplier-retailer transportation system is investigated as a two-echelon environment. There is a single location in each echelon; the unique supplier at the first echelon has to replenish the retailer's warehouse at the second echelon. By the way, the shortage situation should be avoided. For this situation, a model is provided based on the traditional EOQ model. The inventory ...

Resource constrained project scheduling problem (RCPSP) is mainly investigated with the objective of either minimizing project makespan or maximizing project net present value. However, when material planning plays a key role in a project, the existing models cannot help determining material ordering plans to minimize material costs. In this paper, the RCPSP incorporated with the material order...

in this article, a finite horizon, multi product and multi period economic order quantity like seasonal items is considered where demand rate is deterministic and known but variable in each period. the order quantities of items come in batch sizes and the end of the period order quantity and, consequently, demand of customers are zero. in addition, storage space is constrained and the problem ...

Joint economic lot sizing (JELS) addresses integrated inventory models in a supply chain. Most of the studies in this field either do not consider the role of the transportation cost in their analysis or consider transportation cost as a fixed part of the ordering costs. In this article, a model is developed to analyze an incremental quantity discount in transportation cost. Appropriate equatio...