scholarly journals An Inventory Model with Price and Quality Dependent Demand Where Some Items Produced Are Defective

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Tapan Kumar Datta
Keyword(s):  
Quality Index ◽  
Unit Price ◽  
Model Parameters ◽  
Selling Price ◽  
Defective Items ◽  
Joint Determination ◽  
Demand Rate ◽  
Dependent Demand

This paper analyzes an inventory system for joint determination of product quality and selling price where a fraction of items produced are defective. It is assumed that only a fraction of defective items can be repaired/reworked. The demand rate depends upon both the quality and the selling price of the product. The production rate, unit price, and carrying cost depend upon the quality of the items produced. Quality index is used to determine the quality of the product. An algorithm is provided to solve the model with given values of model parameters. Sensitivity analysis has also been performed.

scholarly journals The Effect of the Size of Traffic Analysis Zones on the Quality of Transport Demand Forecasts and Travel Assignments

2018 ◽  
Author(s):  
Mehmet Fatih Altan ◽  
Yunus Emre Ayözen
Keyword(s):  
Regression Model ◽  
Traffic Analysis ◽  
Model Parameters ◽  
The Public ◽  
Employment Density ◽  
Exponential Regression Model ◽  
Demand Forecasts

In this work we have studied the selection criteria for traffic analysis zones and the effects of their size and number on the model’s forecasting capabilities. To do so we have focused on the corridor of İstanbul’s Kadıköy-Kartal Metro Line and evaluated the consistency of demand forecasts and travel assignments versus actual measurements under different sizes of the Traffic Analysis Zones (TAZ). Significant improvements in model accuracy were observed by decreasing the zone size. Specifically, studying the public transport network assignments for the metro line when increasing the number of traffic analysis zones from 540 to 1,788 the root mean square error (RMSE) of forecasted vs. actual station-based counts was reduced by 23%. Subsequently, the study used population density and employment density as independent variables for the determination of the optimal radius for the 1,788 zone area, and applied an exponential regression model. Appropriate model parameters were derived for the above case study. The regression model resulted in R2 values over 0.62.

scholarly journals Optimal Production Planning for Manufacturing Systems with Instantaneous Stock-Dependent Demand and Imperfect Yields

2015 ◽  
Vol 2015 ◽  
pp. 1-14
Author(s):  
Longfei He ◽  
Huangli Peng ◽  
Zhanwen Niu ◽  
Haili Lu ◽  
Xiangli Xie
Keyword(s):  
Manufacturing Systems ◽  
Sensitivity Analyses ◽  
Market Demand ◽  
Defective Items ◽  
Production Run ◽  
Stock Dependent Demand ◽  
Demand Rate ◽  
Capacity Bound ◽  
Control State ◽  
Dependent Demand

We consider an EPL model like manufacturing system in presence of production imperfectness and stock-demand dependence simultaneously. During the production process, the system can evolve from in-control state into out-of-control state at any random time, after which the defective items will be generated likely causing quantity loss. Meanwhile, the market demand rate is instantaneously dependent on the timely holding inventory. The manufacturer has to determine his production run length and cycle time by taking into account possible imperfect production, stock-dependent demand, and inventory holding capacity bound. We empolder a model to capture this problem and develop computational algorithm to solve it. We further conduct numerical studies to validate our model and solving method. Sensitivity analyses are reported to show the effect of parameters on the system performance.

scholarly journals Impact of Energy and Carbon Emission of a Supply Chain Management with Two-Level Trade-Credit Policy

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1569
Author(s):  
Vandana ◽  
S. R. Singh ◽  
Dharmendra Yadav ◽  
Biswajit Sarkar ◽  
Mitali Sarkar
Keyword(s):  
Supply Chain ◽  
Energy Consumption ◽  
Supply Chain Management ◽  
Carbon Emission ◽  
Trade Credit ◽  
Selling Price ◽  
Chain Management ◽  
Optimum Energy ◽  
Demand Rate ◽  
Dependent Demand

Supply chain management aims to integrate environmental thinking with efficient energy consumption into supply chain management. It includes a flexible manufacturing process, more product delivery to customers, optimum energy consumption, and reduced waste. The manufacturing process can be made more flexible through volume agility. In this scenario, production cannot be constant, and with the concept of volume agility, production is taken as a decision variable under the effect of optimum energy consumption. Considering a two-echelon supply chain, we consider a producer and supplier with two-level-trade-credit policies (TLTCP) with the optimum consumption. To reduce the integrated total inventory cost, we believe that demand is a function of the credit period and selling price. The cost function is analyzed, either with the credit period dependent demand rate or with the selling price dependent demand rate through the numerical examples under energy costs. Energy and carbon emission costs are introduced in setup/ordering cost, holding cost, and item cost for producer and supplier. The effect of inflation on the total cost cannot be ignored; this model is being developed for deteriorating items with the simultaneous impact of volume agility, energy, carbon emission cost, and two-level-trade-credit policies with inflation. This supply chain model was solved analytically and obtained the optimum decision variables in a quasi-closed form solution. An illustrative theorem is being utilized to analyze the optimum result for all the decision parameters. The convexity of the objective function is being obtained analytically as well as graphically. Finally, numerical examples and sensitivity analysis are employed to illustrate the present study and with managerial insights.

scholarly journals Profitability Index Maximization in an Inventory Model with a Price- and Stock-Dependent Demand Rate in a Power-Form

Mathematics ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1157
Author(s):  
Valentín Pando ◽  
Luis A. San-José ◽  
Joaquín Sicilia ◽  
David Alcaide-López-de-Pablo
Keyword(s):  
Cycle Time ◽  
Optimal Policy ◽  
Inventory Model ◽  
Selling Price ◽  
Lot Size ◽  
Financial Investment ◽  
Demand Rate ◽  
Holding Cost ◽  
Optimal Values ◽  
Dependent Demand

This paper presents the optimal policy for an inventory model where the demand rate potentially depends on both selling price and stock level. The goal is the maximization of the profitability index, defined as the ratio income/expense. A numerical algorithm is proposed to calculate the optimal selling price. The optimal values for the depletion time, the cycle time, the maximum profitability index, and the lot size are evaluated from the selling price. The solution shows that the inventory must be replenished when the stock is depleted, i.e., the depletion time is always equal to the cycle time. The optimal policy is obtained with a suitable balance between ordering cost and holding cost. A condition that ensures the profitability of the financial investment in the inventory is established from the initial parameters. Profitability thresholds for several parameters, including the scale and the non-centrality parameters, keeping all the others fixed, are evaluated. The model with an isoelastic price-dependent demand is solved as a particular case. In this last model, all the optimal values are given in a closed form, and a sensitivity analysis is performed for several parameters, including the scale parameter. The results are illustrated with numerical examples.

Vendor-Buyer Supply Chain Models With Supplier Default Risk Under Selling Price and Trade Credit Period Dependent Demand

2018 ◽  
pp. 156-173
Author(s):  
Chetansinh R. Vaghela ◽  
Nita H. Shah
Keyword(s):  
Supply Chain ◽  
Default Risk ◽  
Trade Credit ◽  
Stackelberg Game ◽  
Model Parameters ◽  
Selling Price ◽  
Lot Size ◽  
Credit Period ◽  
Proposed Model ◽  
Dependent Demand

This chapter focuses on uncooperative supply chain inventory models when a supplier offers a credit period to the retailer for a fixed period of time. The models are studied with trade credit in Nash game and Supplier-Stackelberg game respectively. First, the authors have presented optimal results for centralized and decentralized decisions with selling price dependent demand and without trade credit. Second, the authors have obtained optimal results under the two games using classical optimization. The total joint profit of the supply chain is maximized with respect to initial lot size, selling price, and trade credit period. Numerical examples are provided to authenticate the proposed model and to provide some managerial insights. Also through sensitivity analysis, important model parameters are examined.

scholarly journals Optimal Pricing and Ordering Policy for Deteriorating Items with Stock-and-Price Dependent Demand and Presale Rebate

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Lianxia Zhao ◽  
Jianxin You
Keyword(s):  
Sensitivity Analysis ◽  
Deteriorating Items ◽  
Time Dependent ◽  
Optimal Pricing ◽  
Selling Price ◽  
Effective Algorithm ◽  
Numerical Examples ◽  
Ordering Policy ◽  
Demand Rate ◽  
Dependent Demand

This paper considers an EOQ inventory model with presale policy for deteriorating items, in which the demand rate depends on both on-hand inventory and selling price. Under the assumption that all the presale orders are fully backlogged with waiting-time dependent rebate, this study develops several propositions and derives optimal pricing and ordering policy by designing an effective algorithm. Two numerical examples are also given to illustrate the effectiveness of the algorithm. Finally, the sensitivity analysis of the main parameters is provided.

A Stochastic Inventory Model with Quality-Dependent Demand

1997 ◽  
Vol 47 (3-4) ◽  
pp. 215-222
Author(s):  
G. Mohan Naidu ◽  
K. V. S. Sarma
Keyword(s):  
Inventory Model ◽  
Optimal Order ◽  
Stochastic Inventory ◽  
Stochastic Inventory Model ◽  
Demand Rate ◽  
Optimum Cost ◽  
Quality Material ◽  
Theoretical Results ◽  
Dependent Demand

This paper deals with an inventory model in which the demand rate is influenced by the quality of the material received . The case considered is a situation in which the consumption rate is adjusted whenever the incoming material does not have the desired quality but still usable. This leads to uncertainity in the inventory cycle and may create unplanned shortages. The model takes into account differential prices of the material based on quality. The behaviour of the optimal order level and the optimum cost has been studied as a function of the probability with which good quality material can be received. Numerical illustrations are given in support of the theoretical results.

scholarly journals A Price-Dependent Demand Model in the Single Period Inventory System with Price Adjustment

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Kamran Forghani ◽  
Abolfazl Mirzazadeh ◽  
Mehdi Rafiee
Keyword(s):  
Optimal Order ◽  
Selling Price ◽  
Inventory Problem ◽  
Demand Model ◽  
Inventory Costs ◽  
Single Period ◽  
Proposed Model ◽  
Demand Rate ◽  
Total Inventory ◽  
Dependent Demand

The previous efforts toward single period inventory problem with price-dependent demand only investigate the optimal order quantity to minimize the total inventory costs; however, there is no method in the literature to avoid unwanted costs due to the deviation between the actual demand and the previously estimated demand. To fill this gap, the present paper supposes that stochastic demand rate with normal distribution is sensitive to the selling price; this means that increasing the selling price would decrease the demand rate and vice versa. After monitoring the consumption trend within a section of the period, a new selling price is implemented to change the demand rate and reduce the shortage or salvage costs at the end of the period. Three functions were suggested to represent the demand rate as a function of selling price, and the numerical analysis was implemented to solve the proposed problem. Finally, an illustrative numerical example was solved for different configurations in order to show the advantages of the proposed model. The results revealed that there is a significant improvement in the system costs when price revision is considered.

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