Alireza Haji

Sharif University of Technology | SHARIF · Department of Industrial Engineering

In the field of supply chain, selecting a suitable green supplier could significantly help us to decrease the cost and the risk involved in the operations as well as increase in the quality and green. In this paper, we develop an integrated two-stage approach based on fuzzy analytic hierarchy process (FAHP) and multi-objective mixed-integer linear...

In this article, we design a revenue-sharing contract to coordinate inventory control decisions in a serial supply chain consisting of one supplier, one vendor, and one retailer. We assume that the retailer faces Poisson demand and his unsatisfied demands will be lost. The retailer applies one-for-one period policy in which he constantly places an...

In this paper, we design a revenue sharing contract to coordinate pricing and inventory control decisions in a serial supply chain consisting of one supplier, one manufacturer and one retailer. We assume that the retailer faces Poisson demand and his unsatisfied demands will be lost. The retailer applies one-for-one period policy in which he consta...

This article deals with a single perishable item, continuous-review, two-echelon serial inventory system consisting of a warehouse and a retailer. Customer demands at the retailer are assumed to be Poisson. All items have a fixed shelf life and start aging on their arrival at the retailer. The demand that cannot be met immediately at the retailer i...

Although inventory control under discrete demand in dynamic quantities and time intervals are very common in reality, existing literature has largely ignored them. In this paper, we investigate the inventory control decisions in a two echelon supply chain consisting of one vendor and several retailers. The vendor supplies a product to several retai...

This paper deals with an i * Corresponding author Email address: nventory system with one central warehouse and a number of identical retailers. We consider perishable-on-the-shelf items; that is, all items have a fixed shelf life and start to age on their arrival at the retailers. Each retailer faces Poisson demand and employs (1, T) inventory p...

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 produc...

Although inventory control under discrete demand in dynamic quantities and time intervals are very common in reality, existing literature has largely ignored them. In this paper, we investigate the inventory control decisions in a two echelon supply chain consists of one vendor and several retailers. The vendor supplies a product to several retaile...

Distribution companies try to meet different goals such as increasing profitability, reducing investment and improving reliability indices. Therefore, distribution network planning has converted into complex multi-objective optimization problems. Mathematicians and operation research experts have developed many methods which can be used for solving...

This research deals with a supply chain consisting of one vendor and several retailers. Every retailer orders a fixed discrete quantity in fixed discrete time intervals. The order quantity and order cycle of each retailer could be different from the others. The vendor orders the required quantity to a supplier to fulfill the received demands. The v...

The objective of the present study is to model and analyzing a two-level supply chain with reverse information exchange in which the manufacturer and the retailer are aware of the status of each other's stocks. To take advantages of this method of information exchange, manufacturers and retailers change their stock policies from traditional base-st...

In this literature, we survey on methods and techniques for solving fuzzy linear programming. We classified the problems in three types of categories, based on fuzziness in constraints, coefficients, right hand sides, and objective function. Some of these methods provide fuzzy solution and the others provide crisp solution. We introduce the methods...

In this paper we consider a system consisting of a supplier with a single processing unit, a repair center, and a retailer with Po isson demand. We assu me th at th e retailer app lies on e-for-one ordering policy with backorders for his inventory control. The retailer's orders form a queue in the supplier processing unit. We also assume that a cer...

In this paper we consider a queueing-inventory system having a supplier with infinite capacity, one rework center with a single server, one warehouse, and Poisson demand. The warehouse replenishment policy is one-for-one, that is, as soon as a demand arrives he orders a unit to the supplier. A certain fraction of the produced items are defective an...

In this paper we consider a single retailer with an attached rework center. Retailer faces a Poisson demand with a known rate and adopts a base stock policy, that is, as soon as a demand arrives he orders a unit to a supplier with an ample stock. All demands must be satisfied. If retailer is out of stock, the demand will be backlogged. The lead tim...

In this paper we consider a single retailer with an attached rework center. Retailer faces a Poisson demand with a known rate and adopts a base stock policy, that is, as soon as a demand arrives he orders a unit to a supplier with an ample stock. All demands must be satisfied. If retailer is out of stock, the demand will be backlogged. The lead tim...

Consider a two-level inventory system consisting of one supplier and one retailer. The retailer faces a Poisson demand with a known rate and applies base stock (one-for-one ordering) policy. That is, his inventory position is set to a predetermined level, so the demand pattern is transferred exactly to the supplier. The supplier has an inventory sy...

Economic lot size scheduling problem (ELSP) for a multi-product single machine system is a classical problem. This paper considers ELSP with budgetary constraint as an important aspect of such systems. In the real world situations the available funds for investment in inventory is limited. By adopting the common cycle time approach to ELSP, we obta...

The objective of this paper is to provide a framework to integrate the existence of products with imperfect-quality items, inspection errors, rework and scrap items into a single Economic Production Quantity (EPQ) model. To achieve this objective, a suitable mathematical model is defined and the optimal production lot size that minimises the total...

The purpose of this paper is to adopt and analyze a new ordering policy called one-for-one-period policy in a multi-echelon supply chain consisting of one retailer and a series of N suppliers. The main advantage of adopting the one-for-one-period (1,T) ordering policy for retailers is the elimination of uncertainty for supplier which leads to total...

This paper attempts to develop the optimal solution for an inventory problem consisting of a single machine which produces items some of which may be defective. We assume that no shortages are allowed and all defective items are to be reworked. Setup cost for rework and waiting time of defectives are considered. We consider two different policies w...

This paper deals with the issue of economic batch quantity (EBQ) in a single machine system in which defective items are produced in each cycle of production. The accumulated defective items produced in a period, consisting of several equal cycles, are all reworked in the last cycle of this period called the rework cycle. At the end of each period...

Rapid market changes, explosion of product varieties and short life cycles have increased competition in today's global markets. It is obvious that in today's competitive markets, collaboration between the vendor and the buyer is necessary to reduce the joint inventory cost and the response time of the vendor-buyer system. Joint Economic Lot sizing...

This paper is focused on the representation and treatment of knowledge and data uncertainty within the context of an important industrial challenge, i.e., new product pricing. The most well known participating factor in pricing process is cost meanwhile the other factors like customer value and firm’s strategy should be considered in the pricing pr...

The classical economic production quantity (EPQ) model is a well-known and commonly used inventory control technique. Common assumptions in this model are that all units produced are of perfect quality and shortage is not allowed, since in practice shortage, non-conforming product or scrap items are possible, these assumptions will underestimate th...

This paper considers a two-level supply chain which consist of a vendor and several retailers. Unsatisfied demands in retailers are lost. We assume that retailers face Poisson demand. The vendor policy is that all retailers have a common service level, that is, the percentages of lost demands at all retailers are the same. Further, there is a budge...

In this paper, we develop an inventory model with price dependant demand rate, under time value of money and inflation, finite time horizon, exponential backlogging rate and exponential deterioration rate with the objective of maximizing the present worth of the total system profit. Using a dynamic programming based solution algorithm, we are able...

This study develops a fuzzy multi-objective linear programming (FMOLP) model for solving the multi-objective no-wait flow shop scheduling problem in a fuzzy environment. The proposed model attempts to simultaneously minimize the weighted mean completion time and the weighted mean earliness. A numerical example demonstrates the feasibility of applyi...

In this paper we consider a single machine system that produces items part of which are defective. The defective items produced in a time period, consisting of several equal cycles, are accumulated and are all reworked in the last cycle of this period called the rework cycle. At the end of the rework cycle the whole process will start all over agai...

In this paper we consider a single stage production system in which defective items are produced in each cycle of production. In the litrature of inventory control when the rework is done on defective items it is assumed that the storage space is unlimited and the setup time for rework is ignored. Here we assume that the storage space is limited an...

In this paper we intend to obtain the economic batch quantity (EBQ) for an imperfect production system in which defective items are produced in each cycle of production. In the litrature of inventory control when the rework is done on defective items it is assumed that the production rate of the rework process is constant and the setup time for rew...

In this paper we introduce the optimal solution for a simple and yet practical inventory policy with the important characteristic which eliminates the uncertainty in demand for suppliers. In this new policy which is different from the classical inventory policies, the time interval between any two consecutive orders is fixed and the quantity of eac...

In this paper we develop two models; the without shortages and the completely backlogging shortages with the price dependant demand rate under time value of money and inflation, finite time horizon and exponentially deterioration rate with the objective of maximizing the present worth of the total system profit. Using the dynamic programming method...

In this paper we consider a two-level inventory system with one warehouse and one retailer with information exchange. Transportation times are constant and retailer faces independent Poisson demand. The retailer applies continuous review (R, Q)-policy. The supplier starts with m initial batches (of size Q), and places an order to an outside source...

This study develops a fuzzy multi-objective liner programming (FMOLP) model for solving the multi-objective no-wait flow shop scheduling problem in fuzzy invironment. The proposed model attempts to minimize weighted mean copmletion time and weighted mean earliness. A numerical example demonestrates the feasibility of applying the proposed model to...

In this paper we consider a single machine multi-product lot scheduling problem in which defective items are produced in any production run of each product. In each cycle after the normal production of each product the machine is setup for the rework of the defectives of the same product and then the rework process starts. We assume that the setup...

In this paper, the designing of a parallel channel queuing system is considered in which it is desirable to serve the customers immediately upon their arrival. To design such a service facility, the �rst and the second moments of the number of customers are obtained in an in�nite channel server under the assumption that the arrival process has a ge...

The classical single-period problem (SPP) is to find a product's order quantity that maximizes the expected profit in a single period under probabilistic demand. In this paper we consider a SPP model in which a percent of the quantity ordered to the supplier contains defective units and is a random variable with a known distribution function. We as...

The classical economic production quantity (EPQ) model is a well-known and commonly used inventory control technique. A common assumption in the EPQ model is that all units produced are of perfect quality, since in practice non-conforming product or scrap items are possible, this assumption will underestimate the actual required quantity. The objec...

The first objective of this paper is to derive the total cost for one of the most commonly used continuous sampling plans in industry. The total cost includes the costs of inspection, reworks, and defective items returned by the customers. The continuous sampling plan under study is commonly known as CSP-1 which consists of alternate sequences of 1...

We adopt the common cycle approach to economic lot scheduling problem and minimize the maximum aggregate inventory. We allow the occurrence of the idle times between any two consecutive products and consider limited capital for investment in inventory. We assume the setup times are negligible. To achieve the optimal investment in inventory we first...

This paper is concentrated to one of challenging industrial problems, i.e. new product pricing and treatment of imprecise knowledge corresponding to it . Although in pricing process, costs are important, other factors should be taken into account like customer value and so on. Other factors like the risks that consumer bear in purchasing new produc...

In this paper we consider a spare parts inventory system in which the inventory policy is a base stock system. It is assumed that the failed parts are not repairable, the arrival of demands for spare parts is a general arrival process which has the stationary and orderliness property, and the replenishment lead time for spares is a random variable...