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Hui-ming Wee - One of the best experts on this subject based on the ideXlab platform.
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Note on ＂An Optimization Model for Products with Limited Production Quantity＂
2015Co-Authors: Hui-ming Teng, Ping-hui Hsu, Hui-ming WeeAbstract:The purpose of this note is to serve as an extension to the article [1] having the same title by authors. In the study above, a newsvendor problem was considered for products with limited Production Quantity: both the unit selling price and customers' demand are influenced by the limited Production Quantity, but the Production cost per unit is assumed to be constant. This paper extends that the Production cost per unit is a function of Production Quantity and then develops to obtain a Production policy such that the expected profit is maximized. This makes the previous model more reasonable and practical.
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An optimization model for products with limited Production Quantity
Applied Mathematical Modelling, 2015Co-Authors: Hui-ming Teng, Ping-hui Hsu, Hui-ming WeeAbstract:Abstract An important strategy for dealing with scarcity and customer response is to produce limited Quantity of certain products. Due to limited Production Quantity, consumers would feel the value or uniqueness of the products and have a stronger urgency to purchase them. Some distribution outlet would raise prices to cover promotion expenses and to increase profit margin. In this study, we consider a newsvendor problem for products with limited Production Quantity: both the unit selling price and customers’ demand are influenced by the limited Production Quantity. An algorithm is developed to obtain a Production policy such that the expected profit is maximized. Numerical examples and sensitivity analysis are presented to illustrate the model.
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An economic Production Quantity model with non-synchronized screening and rework
Applied Mathematics and Computation, 2014Co-Authors: Hui-ming Wee, Wan-tsu Wang, Tsai Chi Kuo, Yung-lung Cheng, Yen-deng HuangAbstract:Abstract This study investigates an economic Production Quantity model for imperfect quality items with non-synchronized screening and rework. With time intervals as decision variables, our approach establishes a feasible optimal policy for the inventory system. We presented a solution procedure to derive the optimal policy, and generalized the proposed model to the classic EPQ model by taking the limiting parameter values for the optimal solution. A numerical example is provided to illustrate the theory and its application.
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A Production Quantity model for imperfect quality items with shortage and screening constraint
International Journal of Production Research, 2013Co-Authors: Hui-ming Wee, Wan-tsu Wang, Po-chung YangAbstract:This study develops an economic Production Quantity (EPQ) model and solution procedure for imperfect items with shortage and screening constraint. The Renewal Reward Theorem (RRT) is applied to formulate the exact expected total profit per unit time. We have shown the robustness of our model using time interval as decision variable rather than the traditional order size and backorder Quantity. A solution procedure is provided to derive the optimal policy. Special cases of the EOQ/EPQ models can be obtained by taking the parameter limiting values. Numerical examples and sensitivity analysis are presented to verify our results.
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Economic Production Quantity model with repair failure and limited capacity
Applied Mathematical Modelling, 2013Co-Authors: Ata Allah Taleizadeh, Hui-ming Wee, Seyed Gholamreza Jalali-nainiAbstract:We develop an economic Production Quantity (EPQ) model with random defective items and failure in repair. The existence of only one machine results with limited Production capacity and shortages. The aim of this research is to derive the optimal cycle length, the optimal Production Quantity and the optimal back ordered Quantity for each product so as to minimize the total expected cost (holding, shortage, Production, setup, defective items and repair costs). The convexity of the model is derived and the objective function is proved convex. Two numerical examples illustrate the practical usage of the proposed method.
Ata Allah Taleizadeh - One of the best experts on this subject based on the ideXlab platform.
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Sustainable economic Production Quantity models for inventory systems with shortage
Journal of Cleaner Production, 2018Co-Authors: Ata Allah Taleizadeh, Vahid Reza Soleymanfar, Kannan GovindanAbstract:Abstract Recently, new economic order/Production Quantity models have shifted away from focusing only on economic issues and towards combined economic-environmental concerns because of sustainable development goals. Despite this shift, only a few works have addressed sustainable Economic Production Quantity (EPQ). The theoretical sustainable EOQ and EPQ models are basic models that ignore many real-life conditions such as the possibility of stock-out in inventory systems. In this paper, we develop four new sustainable economic Production Quantity models that consider different shortage situations. To find optimal values of inventory system variables, we solve four independent profit maximization problems for four different situations. These proposed models include a basic model in which shortages are not allowed, and when shortages are allowed, the lost sale, full backordering and partial backordering models can be selected by operations managers depending on the manufacturer's motivation to improve service levels. We have also proposed an algorithm for determining optimum values of the decision variables for these sustainable economic Production Quantity models. Finally, the formulated models are explained with some different examples and the obtained results have been analyzed and discussed. These results show that the sustainable economic Production Quantity with partial backordering model is a general and more realistic model that can be used in many real cases with a reasonable profit amount, compared with the three other proposed models.
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Economic Production Quantity model with repair failure and limited capacity
Applied Mathematical Modelling, 2013Co-Authors: Ata Allah Taleizadeh, Hui-ming Wee, Seyed Gholamreza Jalali-nainiAbstract:We develop an economic Production Quantity (EPQ) model with random defective items and failure in repair. The existence of only one machine results with limited Production capacity and shortages. The aim of this research is to derive the optimal cycle length, the optimal Production Quantity and the optimal back ordered Quantity for each product so as to minimize the total expected cost (holding, shortage, Production, setup, defective items and repair costs). The convexity of the model is derived and the objective function is proved convex. Two numerical examples illustrate the practical usage of the proposed method.
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multi products single machine economic Production Quantity model with multiple batch size
International Journal of Industrial Engineering Computations, 2011Co-Authors: Ata Allah Taleizadeh, Hui-ming Wee, Gede Agus Widyadana, Jahangir BiabanidAbstract:: Received 10 November 2010 Received in revised form 4 January 2011 Accepted 6 January 2011 Available online 6 January 2011 In this paper, a multi products single machine economic Production Quantity model with discrete delivery is developed. A unique cycle length is considered for all produced items with an assumption that all products are manufactured on a single machine with a limited capacity. The proposed model considers different items such as Production, setup, holding, and transportation costs. The resulted model is formulated as a mixed integer nonlinear programming model. Harmony search algorithm, extended cutting plane and particle swarm optimization methods are used to solve the proposed model. Two numerical examples are used to analyze and to evaluate the performance of the proposed model.
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multi product Production Quantity model with repair failure and partial backordering
Computers & Industrial Engineering, 2010Co-Authors: Ata Allah Taleizadeh, Hui-ming Wee, Seyed Jafar SadjadiAbstract:In this paper, a Production Quantity model with random defective items, service level constraints and repair failure is studied. The existence of only one machine results in limited Production capacity and partial backordering. The aim of this research is to determine the optimal cycle length, optimal Production Quantity and optimal backordered Quantity of each product such that the expected total cost (holding, shortage, Production, setup, defective items and repair costs) is minimized. Two numerical examples and sensitivity analysis are provided to illustrate the practical usage of the proposed method.
Gede Agus Widyadana - One of the best experts on this subject based on the ideXlab platform.
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an economic Production Quantity model for deteriorating items with preventive maintenance policy and random machine breakdown
International Journal of Systems Science, 2012Co-Authors: Gede Agus Widyadana, Hui-ming WeeAbstract:In recent years, many researches on economic Production Quantity EPQ models with machine breakdown and preventive maintenance have been developed, but few of them have developed integrated models for deteriorating items. In this study, we develop EPQ models for deteriorating items with preventive maintenance, random machine breakdown and immediate corrective action. Corrective and preventive maintenance times are assumed to be stochastic and the unfulfilled demands are lost sales. Two EPQ models of uniform distribution and exponential distribution of corrective and maintenance times are developed. An example and sensitivity analysis is given to illustrate the models. For the exponential distribution model, it is shown that the corrective time parameter is one of the most sensitive parameters to the optimal total cost.
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Economic Production Quantity models for deteriorating items with rework and stochastic preventive maintenance time
International Journal of Production Research, 2012Co-Authors: Hui-ming Wee, Gede Agus WidyadanaAbstract:Economic Production Quantity (EPQ) models for deteriorating inventory have been investigated by many researchers in recent years. In this paper, we develop EPQ models for deteriorating items with rework and stochastic preventive maintenance time. The models are solved using a search method, since a closed form solution cannot be derived. A numerical example and sensitivity analysis are provided to evaluate the models. The sensitivity analysis shows that the deteriorating cost has a significant effect on the optimal inventory cost; however, the Production and the demand rate have the most significant effect on the optimal total cost and the optimal Production up-time period.
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multi products single machine economic Production Quantity model with multiple batch size
International Journal of Industrial Engineering Computations, 2011Co-Authors: Ata Allah Taleizadeh, Hui-ming Wee, Gede Agus Widyadana, Jahangir BiabanidAbstract:: Received 10 November 2010 Received in revised form 4 January 2011 Accepted 6 January 2011 Available online 6 January 2011 In this paper, a multi products single machine economic Production Quantity model with discrete delivery is developed. A unique cycle length is considered for all produced items with an assumption that all products are manufactured on a single machine with a limited capacity. The proposed model considers different items such as Production, setup, holding, and transportation costs. The resulted model is formulated as a mixed integer nonlinear programming model. Harmony search algorithm, extended cutting plane and particle swarm optimization methods are used to solve the proposed model. Two numerical examples are used to analyze and to evaluate the performance of the proposed model.
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Economic Production Quantity model for deteriorating inventory with random machine unavailability and shortage
International Journal of Production Research, 2011Co-Authors: Chun-jen Chung, Gede Agus Widyadana, Hui-ming WeeAbstract:Both random machine unavailability and shortage are common occurrences in manufacturing industries. In this paper, machine unavailability is considered in deriving an economic Production Quantity (EPQ) model for deteriorating items. We develop four EPQ models for deteriorating inventory with random machine unavailability and shortage. The study considers lost sales, backorder and two kinds of machine unavailability distributions. Numerical examples are provided to illustrate the theory. Key parameter changes that affect costs are shown in the sensitivity analysis. From the results of the sensitivity analysis, it is shown that the random machine unavailability parameter and holding cost have significant effects on the optimal total cost and Production down-time.
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Economic Production Quantity (EPQ) deteriorating inventory model with machine breakdown and stochastic repair time
2009 IEEE International Conference on Industrial Engineering and Engineering Management, 2009Co-Authors: Gede Agus Widyadana, Hui-ming WeeAbstract:In recent years, many researchers focus their studies on developing practical Economic Production Quantity (EPQ) models. This paper develops an EPQ deteriorating item model with machine breakdown and stochastic repair time. A numerical example and sensitivity analysis are given to illustrate the theory. The results show that Production rate and demand rate are the most sensitive parameters to the optimal Production period, and demand rate is the most sensitive parameter to the optimal total cost.
Mohamad Y. Jaber - One of the best experts on this subject based on the ideXlab platform.
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Deriving an exergetic economic Production Quantity model for better sustainability
Applied Mathematical Modelling, 2016Co-Authors: Hussam Jawad, Mohamad Y. Jaber, Maurice Bonney, Marc A. RosenAbstract:Abstract Businesses strive to be sustainable because of internal and external pressures. To examine sustainability, firms may use different methods of analysis. Extended Exergy Accounting (EEA) - a resource based evaluation method - is such a tool used to examine environmental, social, and economic sustainability. This paper re-examines the economic Production Quantity (EPQ) model, in an attempt to reflect the needs of sustainability. The paper uses EEA and the laws of thermodynamics to measure the sustainability of a Production-inventory system and finds that in some situations sustainability can be profitable. EEA measures the value of a commodity, based on the consumption of the natural and physical resources as opposed to the classical EPQ model, which uses monetary cost. Measuring the exergy consumed during the Production of a commodity shows that the exergetic model developed can deliver better sustainability and profitability than the classical EPQ. This should further encourage companies to move towards sustainable strategies. The results suggest that governments, individuals and other organizations should encourage companies to move towards sustainable strategies.
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Economic Production Quantity model for items with imperfect quality
International Journal of Production Economics, 2000Co-Authors: Moueen K. Salameh, Mohamad Y. JaberAbstract:Abstract The assumptions necessary to justify the use of economic Production Quantity (EPQ/EOQ) models are rarely met. To provide mathematical models that more closely conform to actual inventories and respond to the factors that contribute to inventory costs, the models must be extended or altered. This paper hypothesizes a Production/inventory situation where items, received or produced, are not of perfect quality. Items of imperfect quality; not necessarily defective; could be used in another Production/inventory situation, that is, less restrictive process and acceptance control. The electronics industry gives good examples of such situations. This paper extends the traditional EPQ/EOQ model by accounting for imperfect quality items when using the EPQ/EOQ formulae. This paper also considers the issue that poor-quality items are sold as a single batch by the end of the 100% screening process. A mathematical model is developed and numerical examples are provided to illustrate the solution procedure.
Bor-wen Kreng - One of the best experts on this subject based on the ideXlab platform.
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Operational flexibility and optimal total Production cost in multipleitem economic Production Quantity models
International Journal of Systems Science, 2000Co-Authors: Bor-wen KrengAbstract:This study investigates the problems of operational flexibility, optimal Production rate and Production runs in multiple-item economic Production Quantity models under a rotation cycle basis. The Production rate of each item and the system rotation cycle are crucial decision variables in this study. The unit Production cost of each item is a function of its Production rate. The relationship between the optimal total Production cost and operational flexibility, which is affected by the unit Production cost function of each item, is analysed. Sensitivity analyses have been conducted to evaluate the effects of operational flexibility on the individual parameters of the unit Production cost function. An industrial case has also been presented as an illustration.
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Implementing an optimal policy for set-up time reduction in an economic Production Quantity model
International Journal of Systems Science, 2000Co-Authors: Bor-wen KrengAbstract:An economic Production Quantity (EPQ) system consisting of single and multiple items with an optimal policy of set-up time reduction and a fixed increment cost are discussed in the present study. The set-up time reduction ratio as a decision variable under various cases of demand in the EPQ model is considered. It is assumed that the set-up cost is linearly related to the set-up time. The set-up time reduction ratio and the lot size are solved simultaneously to obtain an optimal value of the total annual cost. Numerical examples are presented to demonstrate the accuracy of the proposed method.
