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.

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 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 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 with Unit Production Cost and Set-Up Cost as Functions of Production Rate

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Behrouz Afshar-Nadjafi
Keyword(s):  
Production Rate ◽  
Production Cost ◽  
Continuous Functions ◽  
Optimal Production ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Epq Model ◽  
Production Quantity ◽  
Set Up ◽  
The Cost

Extensive research has been devoted to economic production quantity (EPQ) problem. However, no attention has been paid to problems where unit production and set-up costs must be considered as functions of production rate. In this paper, we address the problem of determining the optimal production quantity and rate of production in which unit production and set-up costs are assumed to be continuous functions of production rate. Based on the traditional economic production quantity (EPQ) formula, the cost function associated with this model is proved to be nonconvex and a procedure is proposed to solve this problem. Finally, utility of the model is presented using some numerical examples and the results are analyzed.

scholarly journals Pengembangan Model Economic Production Quantity Mengakomodasi Continue dan Discrete Demand serta Kebijakan Rework Secara Simultan

2020 ◽  
Vol 1 (1) ◽  
pp. 8
Author(s):  
Nurike Oktavia ◽  
Henmaidi Henmaidi ◽  
Prima Fithri
Keyword(s):  
Geometric Mean ◽  
Mathematical Formulation ◽  
Production Costs ◽  
Production Cycle ◽  
Total Production ◽  
Inventory Costs ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Epq Model ◽  
Production Quantity

Inventory of finished goods needs to be planned and controlled regularly. Fulfilling customer demand whenever and wherever is the main purpose of the supply. This issue is related to production activities. Many companies use the Economic Production Quantity (EPQ) Model in determining the size of their lot productions. This model is able to show how to minimize total production costs by reducing inventory costs. Customer behavior at PT XYZ makes product delivery divided into 2 types. The first type, finished goods is sent continuously in small amounts called continue demand. The second type, products is sent between certain time intervals in large quantities called discrete demand. Basic EPQ Model’s parameters do not accommodate a system like this. In addition, PT XYZ requires rework for products that do not pass the quality test. Therefore, this research was developed to formulate EPQ model that can accommodate two types of demand, continue and discrete, as well as the existence of rework policy. This study tries to provide another approach in solving the derivation problem using the "Arithmetic-Geometric Mean" method. The results of this study will display a mathematical formulation to find the optimal production cycle time for PT XYZ. Numerical examples are discussed to show practical models.

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.

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 Analisis Jumlah Produksi Kerudung Pada RAR Azkia Bandung Dengan Metode Economic Production Quantity (EPQ)

Matematika ◽  
2017 ◽  
Vol 16 (2) ◽  
Author(s):  
Farid H Badruzzaman ◽  
Erwin Harahap ◽  
Eti Kurniati ◽  
M. Deni Johansyah
Keyword(s):  
Inventory Cost ◽  
Optimal Amount ◽  
Economic Production Quantity ◽  
Economic Production ◽  
Epq Model ◽  
Production Quantity ◽  
Total Inventory ◽  
Optimum Solution ◽  
Optimum Production ◽  
Production Demand

Abstrak. Permasalahan dari persediaan adalah bagaimana menentukan jumlah produksi optimal dengan biaya total persediaan yang minimum. Sebuah persediaan dilakukan tidak lain dengan maksud mengantisipasi dan memenuhi permintaan yang akan datang. Penyimpanan persediaan dalam jangka waktu yang lama akan berdampak pada keusangan dan menurunnya kualitas, sehingga diperlukan perhitungan jumlah persediaan yang optimal. Model persediaan Economic Production Quantity (EPQ) merupakan suatu metode yang digunakan untuk mempertimbangkan jumlah produksi dan jumlah permintaan hasil produksi. Tujuannya adalah dengan menentukan banyaknya produksi yang meminimumkan total biaya persediaan. Penelitian ini bertujuan untuk menghitung jumlah produksi optimum pada perusahaan kerudung. Selama ini, jumlah produksi pada tahun 2017 dan sebelumnya berpedoman pada jumlah pesanan pelanggan ditambah 17,5% dari jumlah permintaan untuk cadangan persediaan. Hasil solusi optimum dengan model EPQ memiliki perbedaan yang signifikan dibandingkan dengan yang selama ini berlaku.Kata Kunci: economic production quantity, persediaan, produksiAbstract. The problem of inventory is how to determine the optimal amount of production with minimum total inventory cost. An inventory is carried out with no other intent to anticipate and meet future demand. Storage of inventory over a long period of time will have an impact on obsolescence and declining quality, so it is necessary to calculate the optimal amount of inventory. Model inventory Economic Production Quantity (EPQ) is a method used to consider the number of production and the number of production demand. The goal is to determine the amount of production that minimizes the total cost of inventory. This study aims to calculate the number of optimum production on the company's hood. So far, the number of production in 2017 and previously guided by the number of customer orders plus 17.5% of the total demand for inventory reserves. The results of the optimum solution with the EPQ model have significant differences compared to those currently in force.Keywords: economic production quantity, inventory, production

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.

Fuzzy Economic Production Quantity Model for Weibull Deteriorating Items with Ramp Type of Demand

2011 ◽  
Vol 2 (3) ◽  
pp. 55-90 ◽  
Author(s):  
R. Uthayakumar ◽  
M. Valliathal
Keyword(s):  
Deteriorating Items ◽  
Quantity Discounts ◽  
Setup Cost ◽  
Economic Production Quantity ◽  
Deterministic Demand ◽  
Economic Production ◽  
Holding Cost ◽  
Production Quantity ◽  
Delay In Payments ◽  
The Cost

This paper discusses an Economic Production Quantity model for Weibull deteriorating items over an infinite time horizon under fuzzy environment. Fuzziness is introduced by allowing the cost components such as setup cost, production cost, holding cost, shortage cost and opportunity cost due to lost sales to certain extent. Triangular fuzzy numbers are used to represent the mentioned costs. Optimum policies of the described models under fuzzy costs are derived. The proposed model can be extended in several ways. For instance, the deterministic demand function to stochastic fluctuating demand patterns could be considered. The model could also be generalized to allow for quantity discounts, as well as permissible delay in payments.

Sign in / Sign up

Export Citation Format

Share Document