Multi-item Inventory Control Research Articles

An Inventory Control Model for MRP Parameterization

This paper is devoted to find optimal inventory control policies in the supply system under random lead time. The objective is to minimize the holding cost while keeping a high customer service level. The method mostly used in practice is MRP, but the problem of minimization of the total cost in the case of a random lead time is usually not considered. The main contribution of this paper is to propose a dynamic multi-item inventory control model for MRP parameterization under random lead time. The approach is based on a Markov chain. It is supposed that demand is constant, and lead times are random variables. The finish models give the optimal value for "planned lead times" for MRP method, in single item and multi-items cases.

Multi-item inventory control: A multicriteria view

The difficulties encountered in the practice of inventory control led us to several criticisms of the classical inventory models. We define another approach for the determination of inventory policies based on the notion of efficient policy surfaces. We extend this notion to multi-item inventory control by defining the concepts of family and aggregate item. Using several attributes, we build families of items. In every family, an aggregate item is built in order for the inventory practitioner to make decisions.

A Study on Multi-Item Inventory Control with a Storage Constraint

A Study on Multi-Item Inventory Control with a Storage Constraint

Decomposition in multi-item inventory control

This paper considers a Lagrangian decomposition approach to a stochastic demand multi-item inventory control problem with a single resource constraint. The work is a generalization of existing decomposition methods.

Grouping multi-item inventory using common cycle periods

Multi-item inventory control may be simplified by grouping items into subgroups with a common order cycle for all the items in each group. The methods provided in the literature for determination of the order cycle values are either suboptimal or computationally inefficient. This note proposes a procedure which finds the optimal values and is also computationally efficient.

Equivalent Formulations of Inventory Control Problems

Abstract A general multi-item periodic-review inventory control problem is formulated in several ways, each reflecting a different point of view of the decision maker. These formulations are evaluated with respect to implementation criteria of: (i) technical difficulty in obtaining an optimal solution from the model, (ii) estimation effort required to find the values of the parameters in the model, (iii) effort needed to maintain the model continuously updated during the inventory management process. The most promising one is then compared with the conventional formulation, where the objective function is expressed as the sum of expected inventory holding and shortage costs. It is shown that both formulations lead to the same optimal solution under a certain budgetary constraint. This result offers an instrument for implementation improvements in inventory control systems.

Improved implementation of inventory control models through equivalent formulations

AbstractThis paper summarizes an actual multi‐item periodic‐review inventory control study conducted in a developing country. The firms of developing countries are usually less fortunate than their counterparts in industrialized countries in terms of management information systems, personnel and other infrastructure to successfully implement the results of research studies. Therefore, the management scientists of these countries are more obliged to formulate managerial problems in such a way that “decision‐framing” models thus developed require the least estimating and updating efforts possible, yet not sacrifice much from the optimal solution which otherwise could have been obtained. In this study, two formulations of an actualinventory control problem, one much easier and less costly to implement than the other, are shown to be equivalent with respect to the optimal solution. This result offers an instrument for implementation improvements in inventory control systems.

Multi-Item Inventory Management with Monetary Objective Function

Abstract This paper summarizes an actual multi-item periodic-review inventory control study where the “order-up-to-S” policy is employed. The objective function is expressed in monetary terms and is optimized subject to a budgetary limit on the maximum amount of money that can be tied up in inventories. The optimal solution is obtained by employing the generalized Lagrange multipliers method. Findings indicate that it is possible to decrease by at least 37.5% the amount of money currently invested in inventories while maintaining an 85-90% service level to customers. In this study a considerable amount of effort is also spent on the estimation of cost parameters, especially the shortage cost.