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 Pengembangan Model Economic Production Quantity (EPQ) dengan Sinkronisasi Demand Kontinu dan Diskrit Secara Simultan

2016 ◽  
Vol 15 (1) ◽  
pp. 78 ◽  
Author(s):  
Nurike Oktavia ◽  
Henmaidi Henmaidi ◽  
Jonrinaldi Jonrinaldi
Keyword(s):  
Total Production ◽  
Lot Size ◽  
Inventory Cost ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Holding Cost ◽  
Epq Model ◽  
Production Quantity ◽  
Set Up ◽  
Production Lot Size

The most popular inventory model to determine production lot size is Economic Production Quantity (EPQ). It shows enterprise how to minimize total production cost by reducing inventory cost. But, three main parameters in EPQ which are demand, machine set up cost, and holding cost, are not suitable to solve issues nowadays. When an enterprise has two types of demand, continue and discrete demand, the basic EPQ would be no longer useful. Demand continues comes from a customer who wants their needs to be fulfilled every time per unit time, while the fulfillment of demand discrete is at a fixed interval of time. A literature review is done by writers to observe other formulation of EPQ model. As there is no other research can be found which adopt this topic, this study tries to develop EPQ model considering two types of demand simultaneously.

Consumer Electronics Enterprise Patent Strategy Based on University-Enterprise Cooperation with a Failure Rate

2014 ◽  
Vol 556-562 ◽  
pp. 6616-6619
Author(s):  
Jun Chen ◽  
Lai Fu Ye
Keyword(s):  
Research And Development ◽  
Failure Rate ◽  
Optimal Number ◽  
Consumer Electronics ◽  
Economic Production Quantity ◽  
Patent Strategy ◽  
Economic Production ◽  
Epq Model ◽  
Production Quantity ◽  
Development Failure

Based on Economic Production Quantity (EPQ) model with certain defective rate, this paper analyses technology patent storage problems in university-enterprise cooperation under the perspective of consumer electronics enterprise, finds out the optimal number and cycle of patent research considering the factor of research and development failure rate.

Patent Storage Research of Cooperation between S&T-Oriented Small-Micro Enterprise and University in Triple Helix Innovation Based on EPQ Model

2013 ◽  
Vol 411-414 ◽  
pp. 2317-2321 ◽  
Author(s):  
Lai Fu Ye ◽  
Shi Bin Su
Keyword(s):  
Triple Helix ◽  
Research Direction ◽  
Optimal Number ◽  
Future Research ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Epq Model ◽  
Production Quantity ◽  
The Government ◽  
And Storage

Based on the government-sponsored economic production quantity(EPQ)model, this paper analyses technology patent storage problems in university-enterprise cooperation under the perspective of S&T-oriented small-micro enterprise, finds out the optimal number and cycle of patent research which can keep S&T-oriented small-micro enterprise the lowest cost of research and storage, then puts forward the future research direction.

scholarly journals Random machine breakdown and stochastic corrective maintenance period on an economic production inventory model with buffer machine and safe period

2020 ◽  
Author(s):  
Brojeswar Pal ◽  
Subhankar Adhikari
Keyword(s):  
Lot Size ◽  
Maintenance Policy ◽  
Corrective Maintenance ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Production Inventory ◽  
Epq Model ◽  
Production Quantity ◽  
Production Lot Size ◽  
Period Duration

In this paper, we have developed an economic production quantity (EPQ) model in which production is executed mainly by the original machine. But when the system faces disruption, the buffer of it continues the production. Here, we incorporate a fixed Safe Period running policy, in which the machine runs interruptedly, whenever production commences.  The disruption of the system may occur at any moment of the time horizon over the safe period, and then, it will go under the corrective maintenance policy. Here, we take that both of the time of disruption and period of maintenance are continuous random variables. We have discussed the model under different safe period duration with corresponding disruption situations. Our main objective is to minimize the expected average total cost for all the cases concerning the production lot size. The model has also been illustrated numerically with some examples. To examine the robustness of the solution of this model, we discuss the sensitivity analysis for the parameters.

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 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.

Note on “Effects of Random Defective Rate and Imperfect Rework Process on Economic Production Quantity Model”

2005 ◽  
Vol 128 (1) ◽  
pp. 375-377 ◽  
Author(s):  
Yuan-Shyi Peter Chiu ◽  
Singa Wang Chiu
Keyword(s):  
Algebraic Approach ◽  
Lot Size ◽  
Inventory Cost ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Production Inventory ◽  
Epq Model ◽  
Production Quantity ◽  
Production Lot Size ◽  
Rework Process

Conventional approaches for deriving optimal production lot size are by using the differential calculus on the production-inventory cost function with the need to prove optimality first. Recent articles proposed the algebraic approach to the solution of classic economic order quantity and economic production quantity (EPQ) model without reference to the use of derivatives. This note extends it to an EPQ model taking the random defective rate and imperfect rework process into consideration. We demonstrate that the optimal lot size can be solved algebraically and the expected inventory cost can be derived immediately as well.

scholarly journals An Extended EPQ-Based Problem with a Discontinuous Delivery Policy, Scrap Rate, and Random Breakdown

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Singa Wang Chiu ◽  
Hong-Dar Lin ◽  
Ming-Syuan Song ◽  
Hsin-Mei Chen ◽  
Yuan-Shyi P. Chiu
Keyword(s):  
Real Life ◽  
Optimization Techniques ◽  
Retail Stores ◽  
Total System ◽  
Defective Items ◽  
Economic Production ◽  
Holding Cost ◽  
Epq Model ◽  
Production Quantity ◽  
Delivery Policy

In real supply chain environments, the discontinuous multidelivery policy is often used when finished products need to be transported to retailers or customers outside the production units. To address this real-life production-shipment situation, this study extends recent work using an economic production quantity- (EPQ-) based inventory model with a continuous inventory issuing policy, defective items, and machine breakdown by incorporating a multiple delivery policy into the model to replace the continuous policy and investigates the effect on the optimal run time decision for this specific EPQ model. Next, we further expand the scope of the problem to combine the retailer’s stock holding cost into our study. This enhanced EPQ-based model can be used to reflect the situation found in contemporary manufacturing firms in which finished products are delivered to the producer’s own retail stores and stocked there for sale. A second model is developed and studied. With the help of mathematical modeling and optimization techniques, the optimal run times that minimize the expected total system costs comprising costs incurred in production units, transportation, and retail stores are derived, for both models. Numerical examples are provided to demonstrate the applicability of our research results.

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

2006 ◽  
Vol 2006 ◽  
pp. 1-13 ◽  
Author(s):  
Yuan-Shyi Peter Chiu
Keyword(s):  
Decision Making ◽  
Mathematical Analysis ◽  
Service Level ◽  
Lot Size ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Epq Model ◽  
Production Quantity ◽  
The Relationship ◽  
Required Service

We study the effect of service level constraint on the economic production quantity (EPQ) model with random defective rate. We first prove that the expected overall cost for imperfect quality EPQ model with backlogging permitted is less than or equal to that of the same model without backlogging. Secondly, the relationship between “imputed backorder cost” and maximal shortage level is derived for decision-making on whether the required service level is achievable. Then an equation is proposed for calculating the intangible backorder cost for the situation when the required service level is not attainable. By including this intangible backorder cost in the mathematical analysis, one can derive a new optimal lot-size policy that minimizes expected total costs as well as satisfies the service level constraint. Numerical example is provided to demonstrate its practical usage.

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