scholarly journals Economic production quantity concerning learning and the reworking of imperfect items

2012 ◽  
Vol 22 (2) ◽  
pp. 313-336 ◽  
Author(s):  
Deng-Maw Tsai ◽  
Ji-Cheng Wu
Keyword(s):  
Production Quality ◽  
Optimal Operation ◽  
Defective Items ◽  
Total Cost ◽  
Imperfect Quality ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Imperfect Items ◽  
Epq Model ◽  
Production Quantity

The classical economic production quantity (EPQ) model assumes that items produced are of perfect quality and the production rate is constant. However, production quality depends on the condition of the process. Due to process deterioration or other factors, the production process may shift and produce imperfect quality items. These imperfect quality items sometimes can be reworked and repaired; hence, overall production-inventory costs can be reduced significantly. In addition, it can be found in practice that the time or cost required to repetitively produce a unit of a product decreases when the number of units produced by a worker or a group of workers increases. Under this circumstance, the unit production cost cannot be regarded as constant and, therefore, cannot be ignored when taking account of the total cost. This paper incorporates the effects of learning and the reworking of defective items on the EPQ model since they were not considered in existing models. An optimal operation policy that minimizes the expected total cost per unit time is derived. A numerical example is provided to illustrate the proposed model. In addition, sensitivity analysis is performed and discussed.

Economic production quantity (EPQ) model with partial backordering and a discount for imperfect quality batches

2018 ◽  
Vol 56 (18) ◽  
pp. 6279-6293 ◽  
Author(s):  
Luiza Ribeiro Alves Cunha ◽  
Ana Paula Santos Delfino ◽  
Kamila Almeida dos Reis ◽  
Adriana Leiras
Keyword(s):  
Imperfect Quality ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Partial Backordering ◽  
Epq Model ◽  
Production Quantity

scholarly journals Economic Production Quantity (EPQ) model for three type imperfect items with rework and learning in setup

2013 ◽  
Vol 4 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Arindum Mukhopadhyay ◽  
Adrijit Goswami
Keyword(s):  
Model Performance ◽  
Lot Size ◽  
Setup Cost ◽  
Imperfect Quality ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Production Run ◽  
Imperfect Items ◽  
Production Quantity ◽  
Set Up

Imperfect quality Items are unavoidable in an Inventory system due to imperfect productionprocess, natural disasters, damages, or many other reasons. The setup cost and production cycletime can be related in terms of process deterioration and learning and forgetting effects. Learningreduces production run length and setup cost, whereas deterioration and forgetting increases both.Keeping these facts in mind, this paper investigates an Economic Production Quantity (EPQ) modelwith imperfect quality items with varying set-up costs. Mathematical model and solution proceduresare developed with major insight to its charecteristics. Numerical example and sensitivity analysisare provided to illustrate and analyze the model performance. It is observed that our model has asignificant impacts on the optimal lot size and optimal profit of the model.Classication: 90B05

scholarly journals An EPQ Model for Deteriorating Production System and Items with Rework

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
N. Li ◽  
Felix T. S. Chan ◽  
S. H. Chung ◽  
Allen H. Tai
Keyword(s):  
Production System ◽  
Time Intervals ◽  
Total Cost ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Production Run ◽  
Epq Model ◽  
Production Quantity ◽  
Normal Production ◽  
The Impact

This paper investigates the economic production quantity model jointly considering product deterioration and a deteriorating production system with rework. In this imperfect deteriorating production system, not only does the machine produce defective product but also the machine is subjected to quality deterioration. To be more specific, the defective rate increases at certain time intervals. The defects produced are stored until the end of normal production process. Then they are reworked with extra cost to restore their quality and regarded as perfect product. The main objective is to minimize the total cost per unit product by determining the optimal combination of production run time and backlog quantity. Numerical experiments are carried out to illustrate the behavior of the inventory and show the impact of different parameters on the model. Discussion and conclusions are made at the end of the paper.

scholarly journals An EPQ model with imperfect items using interval grey numbers

2014 ◽  
Vol 5 (1) ◽  
pp. 21-32 ◽  
Author(s):  
Erdal Aydemir ◽  
Fevzi Bedir ◽  
Gultekin Ozdemir ◽  
Abdullah Eroglu
Keyword(s):  
Production Process ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Proposed Model ◽  
Imperfect Items ◽  
Manufactured Products ◽  
Demand Rate ◽  
Imperfect Production Process ◽  
Epq Model ◽  
Production Quantity

The classic economic production quantity (EPQ) model has been widely used to determine the optimal production quantity. However, the analysis for finding an EPQ model has many weaknesses which lead many researchers and practitioners to make extensions in several aspects on the original EPQ model. The basic assumption of EPQ model is that 100% of manufactured products are non-defective that is not valid for many production processes generally. The purpose of this paper is to develop an EPQ model with grey demand rate and cost values with maximum backorder level allowed with the good quality items in units under an imperfect production process. The imperfect items are considered to be low quality items which are sold to a particular purchaser at a lower price and, the others are reworked and scrapped. A mathematical model is developed and then an industrial example is presented on the wooden chipboard production process for illustration of the proposed model. 

scholarly journals Nonlinear pentagonal intuitionistic fuzzy number and its application in EPQ model under learning and forgetting

2021 ◽  
Author(s):  
Avishek Chakraborty ◽  
Shilpi Pal ◽  
Sankar Prasad Mondal ◽  
Shariful Alam
Keyword(s):  
Fuzzy Number ◽  
Numerical Study ◽  
Intuitionistic Fuzzy Number ◽  
Defective Items ◽  
Economic Production Quantity ◽  
Intuitionistic Fuzzy ◽  
Basic Model ◽  
Economic Production ◽  
Epq Model ◽  
Production Quantity

AbstractIn this current era, the concept of nonlinearity plays an important and essential role in intuitionistic fuzzy arena. This article portrays an impression of different representation of nonlinear pentagonal intuitionistic fuzzy number (PIFN) and its classification under different scenarios. A new de-intuitification technique of non-linear PIFN is addressed in this article along with its various graphical representations. Additionally, in this paper, we have observed this by applying it in an economic production quantity model where the production is not perfect and defective items are produced which are reworked. The model is considered under learning and forgetting, where learning is considered as linear, nonlinear PIFN and crisps arena. It is observed from the numerical study that high learning effects in rework lead to decrease in production of defective item, which, besides an economic advantage, may have a positive effect on the environment. Even though forgetting has an adverse effect, the average total cost is much less than that of the basic model which ignores worker learning and forgetting. Finally, comparative and sensitivity analysis result shows the utility of this noble work.

scholarly journals Replenishment policy for an economic production quantity model considering rework and multiple shipments

2020 ◽  
Vol 9 (3) ◽  
pp. 758
Author(s):  
Usman Ghani ◽  
Mubashir Hayat
Keyword(s):  
Cost Function ◽  
Real Life ◽  
Optimal Number ◽  
Lot Size ◽  
Defective Items ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Long Run ◽  
Epq Model ◽  
Production Quantity

Determining the optimal replenishment lot size and shipment policy for a production setup has been of greater interest during the last few years. This paper derives the optimal replenishment lot size and shipment policy for an Economic Production Quantity (EPQ) model with rework of defective items. However, in a real life situation, multi-shipment policy is used in lieu of continuous issuing policy and generation of defective items is inevitable. The proposed research assume that all imperfect quality items are reworked to perfect quality items and then all perfect quality items are delivered to the customers. Mathematical modeling is used in this study and the long-run average production–inventory-delivery cost function is derived. Convexity of the cost function is proved by using the Hessian matrix equations. The closed-form optimal replenishment lot size and optimal number of shipments that minimize the long-run average costs for such an EPQ model are derived.  

scholarly journals The effect of service constraint on EPQ model with random defective rate

2006 ◽  
Vol 2006 ◽  
pp. 1-5 ◽  
Author(s):  
Yung-Fu Huang
Keyword(s):  
Annual Cost ◽  
Differential Calculus ◽  
Cost Minimization ◽  
Algebraic Approach ◽  
Optimal Solution ◽  
Service Level ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Epq Model ◽  
Production Quantity

Chiu studied the effect of service-level constraint on the economic production quantity (EPQ) model with random defective rate. In this note, we will offer a simple algebraic approach to replace his differential calculus skill to find the optimal solution under the expected annual cost minimization.

A NOTE ON EPQ MODEL FOR SEASONAL PERISHABLE PRODUCTS WITH STOCK DEPENDENT DEMAND

2008 ◽  
Vol 25 (03) ◽  
pp. 301-315 ◽  
Author(s):  
S. PANDA ◽  
S. SAHA ◽  
M. BASU
Keyword(s):  
Perishable Products ◽  
Programming Technique ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Time Period ◽  
Capacity Level ◽  
Proposed Model ◽  
Production Inventory ◽  
Epq Model ◽  
Production Quantity

A single item, single cycle economic production quantity model for perishable products is proposed where the demand is two-component and stock dependent. The production inventory scenario of products like cake, bread, fast foods, fishes, garments, cosmetics etc in the festival season is considered. The profit function is formulated under the assumption that the time period of the festival seasons is fixed and the display capacity of the produced item is limited. In the formulation process, to introduce more flexibility, a goal programming technique is incorporated to achieve the producer's desired profit and stock of as much inventory as possible below the display capacity level. A numerical example is presented to illustrate the proposed model. A sensitivity analysis of the model is also carried out.

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