scholarly journals Multi-Objective Inventory Model with Lead-Time and Defective Items

2019 ◽  
Vol 9 (2) ◽  
pp. 2415-2420
Keyword(s):  
Lead Time ◽  
Inventory Model ◽  
Inventory Problem ◽  
Defective Items ◽  
Multi Objective ◽  
Deterministic Demand ◽  
Decision Making Problem ◽  
Holding Cost ◽  
Total Inventory

Inventory problem are generally classified under decision making problem where lead time plays an important role in performance and services to customers during supply and placement of order of an item orders can be placed in shorter lead time with higher price or in longer lead time with lower cost. In this paper we have formulated multi-objective inventory model with one objective of minimizing the total inventory cost and other objective of maintaining the quality of the product by discarding the defective items. The model involved the deterministic demand, lead time dependent lead time cost, holding cost, ordering cost and inspection cost for inspecting defective items. The techniques of priority goal programming and genetic algorithm are applied and the results are compared. The sensitivity analysis is explained due to restriction in cost parameter. The model is finally illustrated with a numerical example.

scholarly journals An Inventory Model with Power Demand Pattern, Weibull Distribution Deterioration and without Shortages

2012 ◽  
Vol 2 ◽  
pp. 33-37
Author(s):  
R. Babu Krishnaraj ◽  
K. Ramasamy
Keyword(s):  
Weibull Distribution ◽  
Inventory Model ◽  
Power Demand ◽  
Inventory Problem ◽  
Mathematical Methods ◽  
Inventory Cost ◽  
Demand Pattern ◽  
Deterministic Demand ◽  
Total Inventory ◽  
Weibull Distribution Deterioration

An inventory problem can be solved by using several methods starting from trial and error methods to mathematical and simulation methods. Mathematical methods help in deriving certain rule and which may suggest how to minimize the total inventory cost in case of deterministic demand. Here an attempt has been made for obtaining a deterministic inventory model for power demand pattern incorporating two-parameter Weibull distribution deterioration and without shortages.

scholarly journals Investing in Lead-Time Variability Reduction in a Quality-Adjusted Inventory Model with Finite-Range Stochastic Lead-Time

2008 ◽  
Vol 2008 ◽  
pp. 1-13 ◽  
Author(s):  
Farrokh Nasri ◽  
Javad Paknejad ◽  
John Affisco
Keyword(s):  
Lead Time ◽  
Variance Reduction ◽  
Inventory Model ◽  
Time Variability ◽  
Defective Items ◽  
Reduction Model ◽  
Time Variance ◽  
Total Inventory ◽  
Truncated Normal ◽  
The Impact

We study the impact of the efforts aimed at reducing the lead-time variability in a quality-adjusted stochastic inventory model. We assume that each lot contains a random number of defective units. More specifically, a logarithmic investment function is used that allows investment to be made to reduce lead-time variability. Explicit results for the optimal values of decision variables as well as optimal value of the variance of lead-time are obtained. A series of numerical exercises is presented to demonstrate the use of the models developed in this paper. Initially the lead-time variance reduction model (LTVR) is compared to the quality-adjusted model (QA) for different values of initial lead-time over uniformly distributed lead-time intervals from one to seven weeks. In all cases where investment is warranted, investment in lead-time reduction results in reduced lot sizes, variances, and total inventory costs. Further, both the reduction in lot-size and lead-time variance increase as the lead-time interval increases. Similar results are obtained when lead-time follows a truncated normal distribution. The impact of proportion of defective items was also examined for the uniform case resulting in the finding that the total inventory related costs of investing in lead-time variance reduction decrease significantly as the proportion defective decreases. Finally, the results of sensitivity analysis relating to proportion defective, interest rate, and setup cost show the lead-time variance reduction model to be quite robust and representative of practice.

scholarly journals Inventory model for deteriorating items with negative exponential demand, probabilistic deterioration and fuzzy lead time under partial back logging

2020 ◽  
Vol 30 (3) ◽  
Author(s):  
Nabendu Sen ◽  
Sumit Saha
Keyword(s):  
Inventory Management ◽  
Lead Time ◽  
Probability Distributions ◽  
Optimal Strategies ◽  
Inventory Model ◽  
Deteriorating Items ◽  
Optimal Time ◽  
Inventory Cost ◽  
Total Inventory ◽  
Negative Exponential

The effect of lead time plays an important role in inventory management. It is also important to study the optimal strategies when the lead time is not precisely known to the decision makers. The aim of this paper is to examine the inventory model for deteriorating items with fuzzy lead time, negative exponential demand, and partially backlogged shortages. This model is unique in its nature due to probabilistic deterioration along with fuzzy lead time. The fuzzy lead time is assumed to be triangular, parabolic, trapezoidal numbers and the graded mean integration representation method is used for the defuzzification purpose. Moreover, three different types of probability distributions, namely uniform, triangular and Beta are used for rate of deterioration to find optimal time and associated total inventory cost. The developed model is validated numerically and values of optimal time and total inventory cost are given in tabular form, corresponding to different probability distribution and fuzzy lead-time. The sensitivity analysis is performed on variation of key parameters to observe its effect on the developed model. Graphical representations are also given in support of derived optimal inventory cost vs. time.

The (s,Q) inventory model with Erlang lead time and deterministic demand

2004 ◽  
Vol 51 (6) ◽  
pp. 906-923 ◽  
Author(s):  
Jeon G. Kim ◽  
Daewon Sun ◽  
Xin James He ◽  
Jack C. Hayya
Keyword(s):  
Lead Time ◽  
Inventory Model ◽  
Deterministic Demand

scholarly journals Inventory Model with Partial Backordering When Backordered Customers Delay Purchase after Stockout-Restoration

2016 ◽  
Vol 2016 ◽  
pp. 1-16
Author(s):  
Ren-Qian Zhang ◽  
Yan-Liang Wu ◽  
Wei-Guo Fang ◽  
Wen-Hui Zhou
Keyword(s):  
Layer Structure ◽  
Inventory Model ◽  
Inventory Cost ◽  
Cost Component ◽  
Lipschitz Optimization ◽  
Partial Backordering ◽  
Demand Rate ◽  
Holding Cost ◽  
Total Inventory ◽  
Inventory Holding

Many inventory models with partial backordering assume that the backordered demand must be filled instantly after stockout restoration. In practice, however, the backordered customers may successively revisit the store because of the purchase delay behavior, producing a limited backorder demand rate and resulting in an extra inventory holding cost. Hence, in this paper we formulate the inventory model with partial backordering considering the purchase delay of the backordered customers and assuming that the backorder demand rate is proportional to the remaining backordered demand. Particularly, we model the problem by introducing a new inventory cost component of holding the backordered items, which has not been considered in the existing models. We propose an algorithm with a two-layer structure based on Lipschitz Optimization (LO) to minimize the total inventory cost. Numerical experiments show that the proposed algorithm outperforms two benchmarks in both optimality and efficiency. We also observe that the earlier the backordered customer revisits the store, the smaller the inventory cost and the fill rate are, but the longer the order cycle is. In addition, if the backordered customers revisit the store without too much delay, the basic EOQ with partial backordering approximates our model very well.

scholarly journals Controllable deterioration rate for time-dependent demand and time-varying holding cost

2014 ◽  
Vol 24 (1) ◽  
pp. 87-98 ◽  
Author(s):  
Vinod Mishra
Keyword(s):  
Linear Function ◽  
Inventory Model ◽  
Deteriorating Items ◽  
Inventory Cost ◽  
Deterioration Rate ◽  
Preservation Technology ◽  
Demand Rate ◽  
Holding Cost ◽  
Total Inventory ◽  
Dependent Demand

In this paper, we develop an inventory model for non-instantaneous deteriorating items under the consideration of the facts: deterioration rate can be controlled by using the preservation technology (PT) during deteriorating period, and holding cost and demand rate both are linear function of time, which was treated as constant in most of the deteriorating inventory models. So in this paper, we developed a deterministic inventory model for non-instantaneous deteriorating items in which both demand rate and holding cost are a linear function of time, deterioration rate is constant, backlogging rate is variable and depend on the length of the next replenishment, shortages are allowed and partially backlogged. The model is solved analytically by minimizing the total cost of the inventory system. The model can be applied to optimizing the total inventory cost of non-instantaneous deteriorating items inventory for the business enterprises, where the preservation technology is used to control the deterioration rate, and demand & holding cost both are a linear function of time.

scholarly journals Optimal policies for inventory model with shortages, time-varying holding and ordering costs in trapezoidal fuzzy environment

2021 ◽  
Vol 12 (2) ◽  
pp. 557-574
Author(s):  
Pavan Kumar
Keyword(s):  
Fuzzy Model ◽  
Continuous Functions ◽  
Inventory Model ◽  
Inventory Problem ◽  
Distance Method ◽  
Fuzzy Environment ◽  
Optimal Policies ◽  
Demand Rate ◽  
Holding Cost ◽  
Fuzzy Inventory

This paper proposes the optimal policies for a fuzzy inventory model considering the holding cost and ordering cost as continuous functions of time. Shortages are allowed and partially backlogged. The demand rate is assumed in such to be linearly dependent on time during on-hand inventory, while during the shortage period, it remains constant. The inventory problem is formulated in crisp environment. Considering the demand rate, holding cost and ordering cost as trapezoidal fuzzy numbers, the proposed problem is transformed into fuzzy model. For this fuzzy model, the signed distance method of defuzzification is applied to determine the average total cost (ATC) in fuzzy environment. The objective is to optimize the ATC and the order quantity. One solved example is provided in order to show the applicability of the proposed model. The convexity of the cost function is verified with the help of 3D-graph.

Sign in / Sign up

Export Citation Format

Share Document