Inventory management is considered as major concerns of every organization. In inventory holding, many steps are taken by managers that result a cost involved in this row. This cost may not be constant in nature during time horizon in which perishable stock is held. To investigate on such a case, this study proposes an optimization of inventory model where items deteriorate in stock conditions. To generalize the decaying conditions based on location of warehouse and conditions of storing, the rate of deterioration follows the Weibull distribution function. The demand of fresh item is declining with time exponentially (because no item can always sustain top place in the list of consumers’ choice practically e.g. FMCG). Shortages are allowed and backlogged, partially. Conditions for global optimality and uniqueness of the solutions are derived, separately. The results of some numerical instances are analyzed under various conditions.

This paper deals with developing an inventory model for two warehouses. In today’s business era, there are various types of conditions such as discounts, bulk storage and seasonal products forcing the buyer to purchase the order more than owned warehouse capacity. To store the excess unit of purchase order, buyer arrange additional storage space called as rented warehouse. It is known that the demand of the seasonal products (as woolen garments) increases at the beginning of the season up to a certain time and then stabilizes to a constant rate for the remaining time of the season. The ramp type demand rate forces the buyer to store a higher quantity of the product at the beginning of the season. Most of the physical goods undergo decay or deterioration over time so we study deteriorating seasonal products in this paper. This two warehouse inventory model is developed with inflation and shortages. The model starts with rent warehouse, in first rent warehouse’s inventory level is depleted due to demand and deterioration. At this time own warehouse is depleted due to deterioration only. But after that the inventory level of owned warehouse is depleted due to both demand and deterioration. The shortages are considered in owned warehouse, which is partially backlogged. Numerical solution of the model is obtained to verify the optimal solution. Comprehensive sensitivity analysis has been carried out for showing the effect of variations in the parameters. The model is solved analytically by minimizing the total cost.

This study deals with an economic order quantity model to find out the optimal selling price and optimal ordering quantity for the products which deteriorates over time. The demand for the products depends on available stock level and selling price of the products. The shortages are allowed, and it is assumed that the occurring shortages are partially backlogged. Depending on the rate of backlogging two models are presented in this study. The first model assumes a constant rate of backlogging, while in second model the backlogging rate is assumed to be dependent on waiting time. Numerical example and sensitivity analysis are presented to illustrate the results of the proposed model.

A two warehouse production inventory model is developed for deteriorating items under reliability consideration. The effect of trade credit is considered under inflation. Since, formulating a suitable inventory model is one of the major concerns for an industry, the main objective of this paper is to optimize the total related cost for reliable production process. The model is illustrated through numerical example. The sensitivity analyses of the cost function are performed due to different measures and some managerial inferences are presented.

This paper deals with the co-ordination of a single producer, multi distributors and multi retailers for a supply chain management to get the maximum profit at minimum investment when shortages is permitted at the retailer‘s end and they are the partially backlogged. Most previous studies on supply chain have dealt with a moderately simpler chain with a single producer and a single buyer. The requirement of the producer is directly proportional to demand of the distributor, while the demand of the distributor is dependent on retailers’ requirement. This passes on rationally to the whole supply chain. The proposed model of this paper considers deteriorating items where the deterioration rate is considered as constant.

During the past few decades, many organizations have attempted to reduce their costs through outsourcing of non-value added activities. This paper presents an empirical investigation to find important factors on reducing production expenses through outsourcing activities. The proposed study of this paper designs a questionnaire in Likert scale consists of 19 questions and distributes it among some experts. Using structural equation modeling, the study investigates different variables and the results indicate that outsourcing could reduce the production cost through time, inventory and human resources. The implementation of Freedman for ranking these factors indicate that time played the most influential factor followed by inventory and human resources. The results of structural equation modeling indicate that there are some positive and meaningful relationship between human capital and cost (B=0.78, t-value = 9.38), a positive and meaningful relationship between inventory and cost (B=0.81, t-value=10.54) and a positive and meaningful relationship between time and cost (B=0.89, t-value = 11.26).

This paper considers the economic order quantity (EOQ) model over a finite horizon, in which demand rate follows a two-parameter Weibull time-dependent, shortages are allowed and completely backlogged. Mathematical formulations are derived under two different circumstances i.e. case I: The permissible delay is less than or equal time to finish positive inventory for settling the account, and case II: The permissible delay period is greater than time to finish positive inventory for settling the account. Based on the optimal solutions some important results are derived and numerical examples are provided to validate the proposed model. Finally, sensitivity analysis is provided to analyze the effect of changes with the variation in one parameter at a time on the optimal solution.

In this paper, a deterministic inventory model with depletion rate dependent holding cost is developed. The demand rate is a power function of the on-hand inventory behind to a certain stock level, at which the demand rate becomes a constant. Shortages are allowed and partially backlogged with the function of waiting time of next replenishment. It is also proved in this model that the optimal replenishment policy not only exists but also is unique. Furthermore, it is provided a simple solution procedure for finding the maximum total profit per unit time. Numerical examples have also been given to illustrate the model and real managerial fact in inventory holding for stock dependent demand.

In general, production system often gets disrupted due to uncertainty and un-planned events, which also affect demands resulting in less abet-margin of a company. With disrupted production system, management would need to study the variation of demand pattern and disruption of system; we have attempted an effort to establish an exponential demand with the production system and solved analytically the problem to determine production time before and after disruptions. Exponentially demand pattern studied, and also we simulate for sensitivity analysis in order to find which parameter is getting significant change for the proposed model.

In this article, a production inventory model is developed to determine the retailer’s optimal replenishment decisions under two levels of trade credit and limited storage space. Two levels of trade credit refers that the supplier provides to his/her retailer a permissible delay period to settle the account and the retailer also in turn provides a delay period to his/her customer for paying of purchasing goods. The retailer’s credit period M offered by supplier is greater than customers credit period N provides by the retailer. This paper investigates retailer optimal replenishment policy under finite replenishment rate by minimizing the total annual inventory cost. Three theorems are developed to determine optimal cycle time, optimal relevant cost and optimal order quantity for retailers accurate and rapidly. A numerical example is used to analyze the validity of propose model, Sensitive analysis shows managerial decisions for retailer.