S. K. Goyal

Recent trends in modeling of deteriorating inventory

Abstract This paper presents a review of the advances of deteriorating inventory literature since the early 1990s. The models available in the relevant literature have been suitably classified by the shelf-life characteristic of the inventoried goods. They have further been sub-classified on the basis of demand variations and various other conditions or constraints. The motivations, extensions and generalizations of various models in each sub-class have been discussed in brief to bring out pertinent information regarding model developments in the last decade.

An integrated inventory model for a single supplier-single customer problem

SUMMARY The method given in this paper is typically applicable to those inventory problems where a product is procured by a single customer from a single supplier. An example has been solved to illustrate the method.

Integrated inventory models: The buyer-vendor coordination

Abstract In this paper, literature dealing with integrated inventory models (buyer-vendor coordination) has been reviewed. A scheme to classify these models is presented. Some future research areas have been identified.

Note on: Economic production quantity model for items with imperfect quality - a practical approach

Abstract In this note we present a simple approach for determining the economic production quantity for an item with imperfect quality. We compare the results based on the simple approach with the optimal method for determining the lot size and show that almost optimal results are obtained using the simple approach.

Buyer vendor coordination models in supply chain management

Coordination between two different business entities is an important way to gain competitive advantage as it lowers supply chain cost. This paper reviews literature dealing with buyer vendor coordination models that have used quantity discount as coordination mechanism under deterministic environment and classified the various models. An effort has also been made to identify critical issues and scope of future research. � 2005 Elsevier B.V. All rights reserved.

Determination of economic production–shipment policy for a single-vendor–single-buyer system

Abstract This paper considers the problem of determining economic production and shipment policy of a product supplied by a vendor to a single buyer. The objective is to minimise the total joint annual costs incurred by the vendor and the buyer.

A review of the joint replenishment problem literature: 1989-2005

The purpose of this paper is to review and summarize the literature on the joint replenishment problem (JRP) since 1989. Our review indicates that while research on the basic form of the JRP under the original classic assumptions may have slowed, there is much interest in new versions of the problem with relaxed assumptions, including dynamic or stochastic demand. Furthermore, recent research on the problem has focused on finding faster algorithms to the classic JRP rather than on improving the solution quality.

Models for multi-plant coordination

Abstract This paper addresses coordination of production planning among multiple plants in a vertically integrated firm. Currently there is no unified body of literature that deals with this issue. We identify important issues that managers and researchers must address so that production and inventory decisions can be determined for all plants in a manner optimal for the organization as a whole.

Retailer's optimal replenishment decisions with credit-linked demand under permissible delay in payments

Usually it is assumed that the supplier would offer a fixed credit period to the retailer but the retailer in turn would not offer any credit period to its customers, which is unrealistic, because in real practice retailer might offer a credit period to its customers in order to stimulate his own demand. Moreover, it is observed that credit period offered by the retailer to its customers has a positive impact on demand of an item but the impact of credit period on demand has received a very little attention by the researchers. To incorporate this phenomenon, we assume that demand is linked to credit period offered by the retailer to the customers. This paper incorporates the concept of credit-linked demand and develops a new inventory model under two levels of trade credit policy to reflect the real-life situations. An easy-to-use algorithm is developed to determine the optimal credit as well as replenishment policy jointly for the retailer. Finally, numerical example is presented to illustrate the theoretical results followed by the sensitivity of various parameters on the optimal solution.

An integrated production-inventory-marketing model for deteriorating items

Generally, inventory control policies for deteriorating items are very sensitive to different marketing policies especially in chemical, food and pharmaceutical industries. Realizing the importance of such inventory policies in practice, an integrated production-inventory-marketing model is developed for determining the economic production quantity (EPQ) and economic order quantity (EOQ) for raw materials in a multi-stage production system. This model considers the effect of different marketing policies such as the price per unit product and the advertisement frequency on the demand of a perishable item. A search method is employed to determine the values of EPQ and EOQ which would result in the maximum total net profit.