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    Coordination mechanism for capacity reservation by considering production time, production rate and order quantity

    , Article Applied Mathematical Modelling ; Volume 37, Issue 20-21 , 2013 , Pages 8796-8812 ; 0307904X (ISSN) Pezeshki, Y ; Akbari Jokar, M. R ; Baboli, A ; Campagne, J. P ; Sharif University of Technology
    In this paper we study the coordination of a dyadic supply chain producing a high-tech product by contracts. The product has a short life cycle and the buyer faces stochastic demands during the selling period. We consider the production time, which causes the inventory costs on supplier's side. As the supplier builds production capacity in advance, the production rate is limited to the capacity created during the production time. In addition, we take into account the inventory cost and operational cost for the buyer. We examine the model under both full information and partial information updating situations, and propose a coordinating contract for each case. Our analysis includes the study... 

    On competence of vendor managed inventory in supply chains using basic mathematical inventory models

    , Article Scientia Iranica ; Vol. 21, issue. 3 , 2014 , p. 1061-1071 Jasemi, M ; Haji, A ; Gharibi, M ; Sharif University of Technology
    In this study, a two-echelon single-vendor supply chain is selected to do a cost-based comparison between short-term performances of a Vendor Managed Inventory (VMI) and a Retailer Managed Inventory (RMI). While the inventory costs include ordering and storing expenses, the rate of consumption and the price of goods are constant, the rate of production and pace of transportation are infinite and shortage is not allowed. This paper, after a comprehensive literature review, is followed by three cases of single retailer, n-retailer and two-retailer chains. Unlike the second case, in the first case, VMI shows an absolute superiority to RMI, and this is the reason for devising the third case in... 

    Optimal strategies for price, warranty length, and production rate of a new product with learning production cost

    , Article Scientia Iranica ; Volume 20, Issue 6 , 2013 , Pages 2247-2258 ; 10263098 (ISSN) Faridimehr, S ; Niaki, S. T. A ; Sharif University of Technology
    This study investigates optimal strategies for price, warranty length, and production rate of a new product in which both static markets for non-durable and dynamic markets for durable products are involved. The mathematical model incorporates both the demand and the cost functions including production, warranty length, and inventory costs. Using the maximum principle approach, the optimal strategies and interactions among price, warranty length, and production rate in both markets are analyzed using some propositions. The analysis shows that to maximize profits in all cases, the price, the warranty length, and the production rate all must go up simultaneously, or one of them must increase... 

    One-for-one period policy in a two-echelon inventory system with commoncycle and poisson demand rate for retailers

    , Article 2009 International Conference on Computers and Industrial Engineering, CIE 2009 ; 2009 , Pages 831-834 ; 9781424441365 (ISBN) Haji, R ; Tayebi, H ; Haji, B ; Sharif University of Technology
    This paper deals with a two-echelon inventory system consisting of onesupplier and N retailers. Each retailer faces an independent Poisson demand withthe same rate and applies a new ordering policy called one-for-one- periodordering policy for its inventory control. In this ordering policy the ordersize is equal to one and the time interval between any two consecutive ordersforms a common fixed cycle. Thus, the supplier faces a deterministic demand andadopts a deterministic inventory policy. At each cycle he orders a batch of sizeN to his own supplier. Upon receipt of each batch he sends 1 unit of theproduct to each retailer with a transportation cost. In this paper, for theabove system we... 

    Determining economic order quantity in a two-level supply chain with transportation cost

    , Article 37th International Conference on Computers and Industrial Engineering 2007, Alexandria, 20 October 2007 through 23 October 2007 ; Volume 2 , 2007 , Pages 1406-1409 ; 9781627486811 (ISBN) Neghab, M. P ; Haji, R ; Sharif University of Technology
    This paper considers a two-level supply chain consisting of one warehouse and a number of identical retailers. Unlike the common practice which determines the optimal ordering policy according to inventory costs only, in this model we consider the transportation cost as well. We suppose that the delivery of each order from the warehouse to any retailer is made by a single vehicle without splitting. We also assume that there are three types of vehicles which are defined as small, medium and large. Each type has its own fixed cost, variable cost, and the capacity size. We assume that the demand rate at each retailer is known and the demand is confined to a single item. Shortages are allowed... 

    Simultaneous coordination of capacity building and price decisions in a decentralized supply chain

    , Article International Journal of Advanced Manufacturing Technology ; Volume 64, Issue 5-8 , 2013 , Pages 961-976 ; 02683768 (ISSN) Pezeshki, Y ; Baboli, A ; Akbari Jokar, M. R ; Sharif University of Technology
    In this paper, we investigate the simultaneous coordination of price and capacity building decisions in a dyadic supply chain. This problem is a combination of capacity reservation problem and pricing problem. While the coordination of supply chain with stochastic demand and fixed prices has received much attention in the literature, price-dependent and stochastic demand has been less considered. We study the latter case where a price-setting retailer faces a linear decreasing demand with respect to price. To capture the uncertainty of the demand, we add a stochastic variable to the demand function. In addition, we incorporate production rate and inventory cost on the supplier side. We... 

    An integrated vendor-buyer inventory model with partial backordering

    , Article Journal of Manufacturing Technology Management ; Volume 23, Issue 7 , 2012 , Pages 869-884 ; 1741038X (ISSN) Moshrefi, F ; Jokar, M. R. A ; Sharif University of Technology
    Purpose - The purpose of this paper is to analyze the effects of supply chain coordination on inventory management while the retailer inventory cycle consists of a shortage period and the backorder rate linearly decreases as a function of shortage duration. It is intended to consider how on-hand inventory and shortage durations are altered when the decisions are centralized. Design/methodology/approach - Mathematical modelling of inventory costs for the retailer and the vendor is used to formulate objective functions. The vendor sets his inventory period as an integer multiple (n) of the retailer inventory cycle in which the integer multiple is a decision variable. Solution spaces of models... 

    A genetic algorithm for vendor managed inventory control system of multi-product multi-constraint economic order quantity model

    , Article Expert Systems with Applications ; Volume 38, Issue 3 , March , 2011 , Pages 2708-2716 ; 09574174 (ISSN) Pasandideh, S. H. R ; Niaki, S. T. A ; Nia, A. R ; Sharif University of Technology
    In this research, an economic order quantity (EOQ) model is first developed for a two-level supply chain system consisting of several products, one supplier and one-retailer, in which shortages are backordered, the supplier's warehouse has limited capacity and there is an upper bound on the number of orders. In this system, the supplier utilizes the retailer's information in decision making on the replenishments and supplies orders to the retailer according to the well known (R, Q) policy. Since the model of the problem is of a non-linear integer-programming type, a genetic algorithm is then proposed to find the order quantities and the maximum backorder levels such that the total inventory... 

    A parameter-tuned genetic algorithm to solve multi-product economic production quantity model with defective items, rework, and constrained space

    , Article International Journal of Advanced Manufacturing Technology ; Volume 49, Issue 5-8 , July , 2010 , Pages 827-837 ; 02683768 (ISSN) Pasandideh, S. H. R ; Akhavan Niaki, S.T ; Mirhosseyni, S. S ; Sharif University of Technology
    The economic production quantity (EPQ) model is often used in manufacturing environments to assist firms in determining the optimal production lot size that minimizes the overall production-inventory costs. While there are some unrealistic assumptions in the EPQ model that limit its real-world applications, in this research, some of these assumptions such as (1) infinite availability of warehouse space, (2) all of the produced items being perfect, and (3) the existence of one product type are relaxed. In other words, we develop a multi-product EPQ model in which there are some imperfect items of different product types being produced such that reworks are allowed and that there is a... 

    Optimal integrated inventory model with lost sale and backordering

    , Article 2009 International Conference on Computers and Industrial Engineering, CIE 2009, 6 July 2009 through 9 July 2009, Troyes ; 2009 , Pages 825-830 ; 9781424441365 (ISBN) Haji, A ; Amiri Elyasi, K ; Save Shemshaki, A ; Sharif University of Technology
    Rapid market changes, explosion of product varieties and short life cycleshave increased competition in today's global markets. It is obvious that intoday's competitive markets, collaboration between the vendor and the buyer isnecessary to reduce the joint inventory cost and the response time of thevendor-buyer system. Joint Economic Lot sizing Problem has been extended in manydifferent directions. Shortage is not allowed in the most of the previousresearches. A few of them considered shortage backordering as a result ofimperfect quality. The purpose of this paper is to recast the Joint economic lotsizing model to be more relevant to current situations, where lost sales and/orbackorders are... 

    Introducing a new ordering policy in a two-echelon inventory system with Poisson demand

    , Article International Journal of Production Economics ; Volume 117, Issue 1 , 2009 , Pages 212-218 ; 09255273 (ISSN) Haji, R ; Neghab, M. P ; Baboli, A
    Elsevier  2009
    In this paper we introduce a new ordering policy for inventory control in a two-echelon inventory system consisting of one central warehouse and a number of non-identical retailers. The warehouse uses a modified one-for-one policy, but the retailers apply a new policy which is different from the traditional inventory policies described in the literature of inventory and production control systems. In this system, each retailer constantly places an order for one unit of product to the central warehouse in a pre-determined time interval; i.e., the time interval between any two consecutive orders from each retailer is a fixed number and the quantity of each order is one. We then show how the...