An EPQ Model of Stock Dependent Demand Subject to Epidemic with Stochastic Lockdown Time

2021 ◽  
Vol 12 (2) ◽  
pp. 2859-2867
Author(s):  
Ruchi Sharma, Et. al.
Keyword(s):  
Production Quality ◽  
Selling Price ◽  
Total Cost ◽  
Economic Production ◽  
Epq Model ◽  
Expected Total Cost ◽  
Classical Economic ◽  
Dependent Demand ◽  
The Ideal

The model created considers the effect of the epidemic on the classical Economic Production Quality (EPQ) model for a production unit exposed to stochastic lockdown time. Expected production time is evaluated utilizing continuous probability density function. The investigation is done to decide the ideal arrangement for the production system which limits the expected total cost per unit time exposed to certain conditions. Here EPQ model is created by taking lockdown time due to epidemic as stochastic.  Machine breakdown affects the manufacturer but disaster like epidemic affects the manufacturer as well as the customer (or in other words, demand). During the production uptime, demand depend upon stock and decline in selling price, but in case of disaster (epidemic) selling price has no consideration and demand depends only on stock. The model is discussed by means of a numerical example and a case study.

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.

scholarly journals Effect of Calculation of Cost of Production on Selling Price of Products Manufacturing Companies in Papua (Case Study CV. Sagita Grafika)

2016 ◽  
Vol 7 (3) ◽  
pp. 6-10
Author(s):  
Mugiati ◽  
Bosta Sihombing
Keyword(s):  
Secondary Data ◽  
Primary Data ◽  
Selling Price ◽  
Manufacturing Companies ◽  
Labor Costs ◽  
Total Cost ◽  
Method Of Calculation ◽  
The Cost ◽  
Costing Analysis

This study aims to determine how the effect of calculating the cost of an order made by the company and the method of calculation of full costing of the product selling price fixing mold. The data used is primary data, order data produced in the period from January 2013 to December 2013, the secondary data obtained from interviews and literature. From these results it can be seen that CV. Sagita Grafika calculate the cost of the product by using the order cost method that produces cost price and the selling price that is incompatible with existing theory, in which the charging of indirect labor and overhead costs shared equally on all types of orders in the amount of Rp. 11.78825 million for indirect labor costs and Rp. 3.1243 million for overhead costs so that volume orders will bear fewer overhead costs equal to the volume of orders more. By using a full costing analysis generated calculation method that the volume of orders that more will earn imposition overhead costs more, because in this calculation loading overhead costs charged by direct labor hours incurred for each order. So that orders with a total volume that many will use a lot of labor hours and vice versa. So in this study that most large orders received charging overhead is the order BS-02 Rp. 31,115,590.92 and most orders received little overhead loading is KK-01 orders in the amount of Rp. 2,208,622.32. Results of a comparison between the cost of the company with the full costing is the total cost of less Rp. 27,499,540.57, the selling price of Rp. 5,866,543.90, while the larger profit generated by using the full costing method that is Rp. 21,632,996.67

scholarly journals A Stochastic Rolling Horizon-Based Approach for Power Generation Expansion Planning

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Hanyun Wang ◽  
Tao Wang ◽  
Xinyi Wang ◽  
Bing Li ◽  
Congmin Ye
Keyword(s):  
Electricity Markets ◽  
Renewable Energy Sources ◽  
Capacity Expansion ◽  
Rolling Horizon ◽  
Total Cost ◽  
Expansion Planning ◽  
Operational Costs ◽  
Expected Total Cost ◽  
Power Generation Expansion Planning

Variable renewable energy sources introduce significant amounts of short-term uncertainty that should be considered when making investment decisions. In this work, we present a method for representing stochastic power system operation in day-ahead and real-time electricity markets within a capacity expansion model. We use Benders’ cuts and a stochastic rolling-horizon dispatch to represent operational costs in the capacity expansion problem (CEP) and investigate different formulations for the cuts. We test the model on a two-bus case study with wind power, energy storage, and a constrained transmission line. The case study shows that cuts created from the day-ahead problem gives the lowest expected total cost for the stochastic CEP. The stochastic CEP results in 3% lower expected total cost compared to the deterministic CEP capacities evaluated under uncertain operation. The number of required stochastic iterations is efficiently reduced by introducing a deterministic lower bound, while extending the horizon of the operational problem by persistence forecasting leads to reduced operational costs.

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 Multi-objective economic production quantity model for fully backlogged problem where demand depend on some conditions and permissible delay in payment

2019 ◽  
Vol 10 (3) ◽  
pp. 1106
Author(s):  
Abhishek Kanti Biswas ◽  
Sahidul Islam
Keyword(s):  
Selling Price ◽  
Defective Items ◽  
Multi Objective ◽  
Economic Production ◽  
Permissible Delay In Payment ◽  
Holding Cost ◽  
Epq Model ◽  
Production Quantity ◽  
Nearest Interval Approximation ◽  
The Cost

For any business, inventory system takes a monumental part. Keep this aspect in mind, we formulate multi-objective displayed EPQ model consider with non-instantaneous deteriorating things where production depends on demand and variable demand pattern depends on display self-space, selling price and frequency of advertisement of the item. The customers are more attracted to buy an item by observing self-space, selling price and advertisement. Imperfect materials are now and again come back to providers for a discount or credit. Here price discount is available for deteriorated and defective items. Holding cost varies with time where shortages are allowed and fully backlogged. Fuzzy environment touches the reality instead of the crisp environment. So, we assumed the cost components as Triangular Fuzzy Numbers and Nearest Interval Approximation Method is used to defuzzify the model. Finally, numerical examples as well as  sketches are given to illustrate the model.

scholarly journals Coordinating Supply Chain Inventory Model for Deteriorating Products

2020 ◽  
Vol 8 (4S5) ◽  
pp. 89-91
Keyword(s):  
Supply Chain ◽  
Numerical Models ◽  
Inventory Model ◽  
Ideal Solution ◽  
Total Cost ◽  
Inventory Replenishment ◽  
Replenishment Policy ◽  
Optimal Values ◽  
Expected Total Cost ◽  
The Ideal

The paper manages an optimal inventory replenishment policy for a deteriorating item with two part coordination technique (coordination and non coordination). The aim of this model is to determine the optimal values for every strategy such that the expected total cost is minimized. The model is solved analytically to get the ideal solution. It is then outlined with the assistance of numerical models.

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