Optimal ordering decision for deteriorating items with expiration date and uncertain lead time (original) (raw)
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Optimal Ordering Decision for Deteriorated Items with Expiration Date and Uncertain Lead Time
The objective of our study is to develop an inventory model of season pattern demand with expiration date in which the deterioration rate is variable. The products which deteriorate with time is known as deteriorating items. The ordering policy is a function of deteriorating rate, expiration date of product, retailer’s seasonal pattern demand and available capital constraint.
2018
In this paper, an inventory model for deteriorating items with selling price and credit period sensitive demand is developed. The inventory system deals with products which have a fixed expiry date after which the product cannot be sold. Here, a permissible delay period is allowed by the supplier to the retailer to pay all his dues, but if the retailer doesn't pay the entire amount at the end of the delay period, an interest will be charged on the remaining dues. The shortages are also allowed and partially backlogged. This paper provides a procedure to develop the total retailer's profit function per unit time of the system and optimal ordering quantity per cycle for the retailer. Finally, the model is illustrated with numerical examples.
International Journal of Advanced Operations Management, 2009
In case of multi-item, the retailer can order the items to the supplier either independently or jointly. In both the situation the cycle inventory for all the items increases because the demand for each item may not be the equal. The goal in multi item inventory system is to decrease total costs by coordinating orders across supply chain. While considering the deteriorating items, the deterioration rate for all the items may differ causing different demand pattern for each item. The present study emphasises on the ordering policies for deteriorating items with varying deterioration rates. A generalised tailored aggregation has been provided, which gives the criteria to select the items according to their order frequency as well as deterioration rate, for placing the order jointly. The model gets reduced to when the items are non-deteriorating (θ = 0). Further, it is shown numerically that the proposed algorithm gives the minimum total cost for the retailer as compared to the independent and joint ordering policy. A case study has been illustrated to present a real life scenario.
International Journal of Advanced Operations Management, 2009
In case of multi-item, the retailer can order the items to the supplier either independently or jointly. In both the situation the cycle inventory for all the items increases because the demand for each item may not be the equal. The goal in multi item inventory system is to decrease total costs by coordinating orders across supply chain. While considering the deteriorating items, the deterioration rate for all the items may differ causing different demand pattern for each item. The present study emphasises on the ordering policies for deteriorating items with varying deterioration rates. A generalised tailored aggregation has been provided, which gives the criteria to select the items according to their order frequency as well as deterioration rate, for placing the order jointly. The model gets reduced to when the items are non-deteriorating (θ = 0). Further, it is shown numerically that the proposed algorithm gives the minimum total cost for the retailer as compared to the independent and joint ordering policy. A case study has been illustrated to present a real life scenario.
Applied Mathematical Modelling, 2014
The retail inventory management literature generally assumes that suppliers seek to stimulate demand by offering retailers a delay in payment. In practice, however, suppliers tend to offer retailers a partial delay in payment. To accommodate this possibility, this paper establishes an economic order quantity model for deteriorating items, with allowable shortages and permissible partial delays in payment based on the order quantity. This paper presents theoretical results to determine the optimal replenishment time and the length of time for the stock to draw down completely, and with these time values the optimal ordering and backlogging policies are calculated for the retailer in order to minimize the total inventory cost per unit time. The optimal solutions are obtained analytically. The inventory model is validated numerically. A sensitivity analysis of the optimal solution with respect to the parameters of the inventory system and managerial insights are given. The proposed inventory model reduces to some existing inventory models.
Mathematical Problems in Engineering, 2009
An inventory system for non-instantaneous deteriorating items with price-dependent demand is formulated and solved. A model is developed in which shortages are allowed and partially backlogged, where the backlogging rate is variable and dependent on the waiting time for the next replenishment. The major objective is to determine the optimal selling price, the length of time in which there is no inventory shortage, and the replenishment cycle time simultaneously such that the total profit per unit time has a maximum value. An algorithm is developed to find the optimal solution, and numerical examples are provided to illustrate the theoretical results. A sensitivity analysis of the optimal solution with respect to major parameters is also carried out.
International Journal of Systems Science, 2012
In this article, an order-level inventory system for deteriorating items has been developed with demand rate as a function of selling price. The demand and the deterioration rate are price dependent and time proportional, respectively. We have considered a perishable item that follows a three-parameter Weibull distribution deterioration. Shortages are not permitted in our model. The optimal solution is illustrated with a numerical example and the sensitivity analysis of parameters is carried out.
This study proposes a single-supplier, singleretailer inventory and pricing strategies for deteriorating items with ramp type demand and a fixed shelf-life under shortage. In practice, there are many commodity such as food, medication exist the shelf life. Therefore the shelf life expiration date has become an important research topic in inventory management. We will discuss three cases. We assume that the inventory objective is to minimize the total cost per unit time of the system. By using the subroutine FindRoot in commercial software Mathematica 5.2, we obtain the optimal solutions Index Terms-Ramp Type Demand Rate; Deteriorating Items; Backlogging I.
An inventory model for deteriorating items with varying demand pattern and unknown time horizon
2011
The primary assumptions with many multi-period inventory lot-sizing models are fixed time horizon and uniform demand variation within each period. In some real inventory situations, however, the time horizon may be unknown, uncertain or imprecise in nature and the demand pattern may vary within a given replenishment period. This paper presents an economic order quantity model for deteriorating items where demand has different pattern with unknown time horizon. The model generates optimal replenishment schedules, order quantity and costs using a general ramp-type demand pattern that allows three-phase variation in demand. Shortages are allowed with full backlogging of demand and all possible replenishment scenarios that can be encountered when shortages and demand pattern variation occur in multi-period inventory modeling are also considered. With the aid of numerical illustrations, the advantages of allowing for variation in demand pattern within replenishment periods, whenever they occur, are explored. The numerical examples show that the length of the replenishment period generated by the model varies with the changes in demand patterns.