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Huiming Wee - One of the best experts on this subject based on the ideXlab platform.
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an integrated production Inventory Model with imperfect production processes and weibull distribution deterioration under inflation
International Journal of Production Economics, 2007Co-Authors: Huiming Wee, Wenchang HuangAbstract:Abstract This study develops an integrated production and Inventory Model from the perspectives of both the manufacturer and the retailer. The Model assumes a varying rate of deterioration, partial backordering, inflation, imperfect production processes and multiple deliveries. The elapsed time until the production process shift is assumed to be arbitrarily distributed. The discounted cash flow and classical optimization technique are used to derive the optimal solution. A numerical example including the sensitivity analysis is given to validate the results of the production-Inventory Model. The integrated decision results in lower optimal joint cost compared with an independent decision by the manufacturer and the retailer.
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two warehouse Inventory Model with partial backordering and weibull distribution deterioration under inflation
Journal of The Chinese Institute of Industrial Engineers, 2005Co-Authors: Huiming Wee, Shtyan LawAbstract:In this study, a two-warehouse Inventory Model with partial backordering and Weibull distribution deterioration is developed. We consider inflation and apply the discounted cash flow in problem analysis. The discounted cash flow (DCF) and optimization framework are presented to derive the optimal replenishment policy that minimizes the total present value cost per unit time. A numerical example and sensitivity analysis are presented to illustrate the Model. When only rented or own warehouse is considered, the present value of the total relevant cost is higher than the case when two-warehouse is considered. From the sensitivity analysis, we show that the total cost of the system is influenced by the deterioration rate, the inflation rate and the backordering ratio.
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integrated Inventory Model for deteriorating items under a multi echelon supply chain environment
International Journal of Production Economics, 2003Co-Authors: Hsin Rau, Meiying Wu, Huiming WeeAbstract:Abstract As the industrial environment becomes more competitive, supply chain management has become essential. The objective of this research is to develop a multi-echelon Inventory Model for a deteriorating item and to derive an optimal joint total cost from an integrated perspective among the supplier, the producer, and the buyer. A computer code is developed to derive the optimal solution. A numerical example is given to illustrate the Model. This paper shows that the integrated approach strategy results in the lowest joint total cost as compared with the independent decision approaches.
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an integrated multi lot size production Inventory Model for deteriorating item
Computers & Operations Research, 2003Co-Authors: P C Yang, Huiming WeeAbstract:The integration of production and Inventory Model is one of the key factors of successful e-business. In this paper we develop a multi-lot-size production and Inventory Model of deteriorating items with constant production and demand rates. By considering the perspectives of both the producer and the buyers, a mathematical Model subject to multi-lot-size production and distribution is developed. The JIT lot-splitting concept from raw material supply to production and distribution is derived. The integration and lot-splitting effects with JIT implementation have contributed significantly to cost reduction.
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deteriorating Inventory Model with quantity discount pricing and partial backordering
International Journal of Production Economics, 1999Co-Authors: Huiming WeeAbstract:Inventory Models with quantity discount, pricing and partial backordering, although common in practice, have received very little attention from researchers. The objective of this study is to develop a deterministic Inventory Model with quantity discount, pricing and partial backordering when the product in stock deteriorates with time. Most retailers make pricing decisions of their products at certain times of the year and these decisions affect demand. In this study the demand rate is assumed to decrease as price for the product increases. Unlike traditional Inventory Models that seek to minimize cost, the objective of this study is to maximize profit. The findings of this study are particularly relevant to retailers of deteriorating products in a competitive environment. A numerical example is given to illustrate the theory.
Manoranjan Maiti - One of the best experts on this subject based on the ideXlab platform.
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Inventory Model of deteriorated items with a constraint a geometric programming approach
European Journal of Operational Research, 2006Co-Authors: Nirmal Kumar Mandal, Tapan Kumar Roy, Manoranjan MaitiAbstract:An Inventory Model for deteriorating items is built-up with limited storage space. Here, demand rate for the items is finite, items deteriorate at constant rates and are replenished instantaneously. Following EOQ Model, the problem is formulated with and without truncation on the deterioration term and ultimately is converted to the minimization of a signomial expression with a posynomial constraint. It is solved by modified geometric programming (MGP) method and non-linear programming (NLP) method. The problem is supported by numerical examples. The results from two versions of the Model (with and without truncation) and two methods (i.e. MGP and NLP) are compared.
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fuzzy Inventory Model with two warehouses under possibility constraints
Fuzzy Sets and Systems, 2006Co-Authors: Manas Kumar Maiti, Manoranjan MaitiAbstract:A multi-item Inventory Model with two-storage facilities is developed with advertisement, price and displayed Inventory level-dependent demand in a fuzzy environment (purchase cost, investment amount and storehouse capacity are imprecise). The Model is formulated as a single/multi-objective programming problem under fuzzy constraint. Constraints are satisfied with some pre-defined necessity and the problem is solved via the Goal Programming Method (GPM) when crisp equivalents of the constraints are available and by a fuzzy simulation-based single/multi-objective genetic algorithm (FSGA/FSMOGA) otherwise. The Model is illustrated with some numerical examples and results from different methods are compared in some particular cases.
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multi objective fuzzy Inventory Model with three constraints a geometric programming approach
Fuzzy Sets and Systems, 2005Co-Authors: Nirmal Kumar Mandal, Tapan Kumar Roy, Manoranjan MaitiAbstract:A multi-item multi-objective Inventory Model with shortages and demand dependent unit cost has been formulated along with storage space, number of orders and production cost restrictions. In most of the real world situations, the cost parameters, the objective functions and constraints of the decision makers are imprecise in nature. Hence the cost parameters, the objective functions and constraints are imposed here in fuzzy environment. This Model has been solved by geometric programming method. The results for the Model without shortages are obtained as a particular case. The sensitivity analysis has been discussed for the change of the cost parameters. The Models are illustrated with numerical examples.
Huchang Liao - One of the best experts on this subject based on the ideXlab platform.
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a note on lead time reduction strategies in a single vendor single buyer integrated Inventory Model with lot size dependent lead times and stochastic demand
International Journal of Production Economics, 2017Co-Authors: Yunlong Cheng, Huchang LiaoAbstract:Glock [2012. Lead time reduction strategies in a single-vendor-single-buyer integrated Inventory Model with lot size-dependent lead times and stochastic demand. International Journal of Production Economics 136, 37–44] recently presented an integrated Inventory Model where the lead time can be reduced by crashing the setup and transportation time, by increasing the production rate, or by decreasing the lot size. In this note, we introduce a more realistic lead time crashing cost and propose a modified integrated Inventory Model by adding the transportation time as a decision variable and assuming that there are two different safety stocks. Furthermore, we give some numerical examples to illustrate the advantages of the modified Model.
Leopoldo Eduardo Cardenasbarron - One of the best experts on this subject based on the ideXlab platform.
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an eoq Inventory Model with nonlinear stock dependent holding cost nonlinear stock dependent demand and trade credit
Computers & Industrial Engineering, 2020Co-Authors: Leopoldo Eduardo Cardenasbarron, Ali Akbar Shaikh, Sunil Tiwari, Gerardo TrevinogarzaAbstract:Abstract This paper deals with an economic order quantity (EOQ) Inventory Model under both nonlinear stock dependent demand and nonlinear holding cost. This Inventory Model is developed from retailer’s point of view, where the supplier offers a trade credit period to the retailer. In this paper, we relax the traditional assumption of zero ending Inventory level to a non-zero ending Inventory level. Consequently, the ending Inventory level can be positive, zero or negative. When the ending Inventory level is negative means that the shortages are permitted and partially backlogged with a constant backlogging rate. Basically, two Inventory Models are developed: (i) an Inventory Model with shortage and (ii) an Inventory Model without shortage. The primary objective of both Inventory Models is to determine the optimal ordering quantity and the ending Inventory level which maximizes the retailer’s total profit per unit time. In order to obtain the optimal solution, lemmas, and theorems are derived along with a solution procedure. The proposed Inventory Models are a general framework as several previously published Inventory Models are particular cases of the Inventory Models derived in this paper. Some numerical examples and a sensitivity analysis are conducted to illustrate the findings of the Inventory Models and some observations are also discussed.
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economic production quantity epq Inventory Model for a deteriorating item with a two level trade credit policy and allowable shortages
2020Co-Authors: Ali Akbar Shaikh, Leopoldo Eduardo Cardenasbarron, Sunil TiwariAbstract:This research work derives an economic production quantity (EPQ) Model, and in order to make it a bit close to reality, the stockout is allowed, and this is completely backordered. In addition to this feature, it is incorporated a two-level credit scheme when both supplier and retailer are giving a delay in payment to their respective customers with the aim of enhancing the sales. The Inventory Model is Modeled as a constrained nonlinear optimization problem, and this is resolved by the generalized reduced gradient method (GRG). Moreover, to exemplify and certify the Inventory Model, five instances are given and solved. Finally, a sensitivity analysis is made for studying the influence of variations of input parameters, modifying one parameter and maintaining the others at their initial input values.
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a generalized economic order quantity Inventory Model with shortage case study of a poultry farmer
Arabian Journal for Science and Engineering, 2019Co-Authors: Amir Hossein Nobil, Amir Hosein Afshar Sedigh, Leopoldo Eduardo CardenasbarronAbstract:We consider an EOQ Inventory Model for growing items, wherein the value and size of items increase during time, some instances of these items are livestock, fish, and poultry. The main difference between this Inventory system and older ones is weight increment of products during stocking without buying more. This paper studies an Inventory system of poultries that new-born items are fed to reach the ideal weight for consumers. In this study, based on the consumers’ preference of fresh foods over frozen items, we assume that shortage is permitted and consumers wait for fresh items when company pays some additional penalties, i.e., the shortage is fully backordered. On the other hand, for each cycle, the producer must prepare the place in terms of hygiene conditions; thus, a setup time per cycle is considered. The aim of this study is to obtain optimum system solution, such that total costs, including setup, purchasing, holding, feeding, and shortage, are minimized. To do so, we employ mathematical measures to approximate growing rates and Model the system as a non-linear programming. To solve the obtained optimization Model, we employ hessian matrix to obtain optimal solution for this Inventory system. The proposed EOQ Inventory Model helps poultry industries in Iran to optimize their system considering costs and permissible shortage, and it can be employed in other countries. Finally, we provide a numerical example and its sensitivity analysis, plus some potential future directions.
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an Inventory Model under price and stock dependent demand for controllable deterioration rate with shortages and preservation technology investment
Annals of Operations Research, 2017Co-Authors: Umakanta Mishra, Ali Akbar Shaikh, Leopoldo Eduardo Cardenasbarron, Sunil Tiwari, Gerardo TrevinogarzaAbstract:This paper develops an EOQ Inventory Model that considers the demand rate as a function of stock and selling price. Shortages are permitted and two cases are studied: (i) complete backordering and (ii) partial backordering. The Inventory Model is for a deteriorating seasonal product. The product’s deterioration rate is controlled by investing in the preservation technology. The main purpose of the Inventory Model is to determine the optimum selling price, ordering frequency and preservation technology investment that maximizes the total profit. Additionally, the paper proves that the total profit is a concave function of selling price, ordering frequency and preservation technology investment. Therefore, a simple algorithm is proposed to obtain the optimal values for the decision variables. Several numerical examples are solved and studied along with a sensitivity analysis.
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two warehouse Inventory Model for deteriorating items with imperfect quality under the conditions of permissible delay in payments
Scientia Iranica, 2017Co-Authors: Chandra K Jaggi, Leopoldo Eduardo Cardenasbarron, Sunil Tiwari, Aliakbar ShafiAbstract:Regularly, manufacturing systems produce perfect and imperfect quality items. The perfect items start deteriorating as soon as these enter to the Inventory. On the other hand, the suppliers provide a delay in payment in order to motivate their buyers to purchase more products. This paper develops a two-warehouse Inventory Model that considers jointly the imperfect quality items, deterioration and one level of trade credit. The proposed Inventory Model optimizes the order quantity to maximize the total profit per unit time. Finally, the proposed Inventory Model and its solution procedure are validated with numerical examples and a sensitivity analysis is done to show how Inventory Model reacts to changes in parameters.
Biswajit Sarkar - One of the best experts on this subject based on the ideXlab platform.
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periodic review fuzzy Inventory Model with variable lead time and fuzzy demand
International Transactions in Operational Research, 2017Co-Authors: Biswajit Sarkar, Amalendu Singha MahapatraAbstract:This paper investigates a periodic review fuzzy Inventory Model with lead time, reorder point, and cycle length as decision variables. The main goal of this study is to minimize the expected total annual cost by simultaneously optimizing cycle length, reorder point, and lead time for the whole system based on fuzzy demand. Two Models are considered in this paper: one with normal demand distribution and another with a distribution-free approach. The Model assumes a logarithmic investment function for lost-sale rate reduction. Furthermore, two separate efficient computational algorithms are explained to obtain the optimal solution. Some numerical examples are given to illustrate the Model.
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quality improvement and backorder price discount under controllable lead time in an Inventory Model
Journal of Manufacturing Systems, 2015Co-Authors: Biswajit Sarkar, Buddhadev Mandal, Sumon SarkarAbstract:Abstract The proposed study investigates a continuous review Inventory Model with order quantity, reorder point, backorder price discount, process quality, and lead time as decision variables. An investment function is used to improve the process quality. Two Models are developed based on the probability distribution of lead time demand. The lead time demand follows a normal distribution in the first Model and in the second Model it does not follow any specific distribution but mean and standard deviation are known. We prove two lemmas to obtain optimal solutions for the normal distribution Model and distribution free Model. Finally, some numerical examples are given to illustrate the Model.
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variable deterioration and demand an Inventory Model
Economic Modelling, 2013Co-Authors: Biswajit Sarkar, Sumon SarkarAbstract:This paper deals with an Inventory Model for deteriorating items with Inventory dependent demand function. Most of the Inventory Models are considered with constant rate of deterioration. In this article, we consider time varying deterioration rate. Based on the demand and Inventory, the Model is considered with three possible cases. We establish the necessary and sufficient conditions for each case to show the existence and uniqueness of the optimal solution. Further, a simple solution algorithm has proposed to obtain the optimal replenishment cycle time and ordering quantity such that the total profit per unit time is maximized. Finally, some numerical examples, sensitivity analysis and graphical representations are provided to illustrate the practical usages of the proposed method.
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a production Inventory Model with probabilistic deterioration in two echelon supply chain management
Applied Mathematical Modelling, 2013Co-Authors: Biswajit SarkarAbstract:Abstract In this study, a production-Inventory Model is developed for a deteriorating item in a two-echelon supply chain management (SCM). An algebraical approach is applied to find the minimum cost related to this entire SCM. We consider three types of continuous probabilistic deterioration function to find the associated cost. The purpose of this study is to obtain the minimum cost with integer number of deliveries and optimum lotsize for the three different Models. Some numerical examples, sensitivity analysis and graphical representation are given to illustrate the Model. A numerical comparison between the three Models is also given.
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an improved Inventory Model with partial backlogging time varying deterioration and stock dependent demand
Economic Modelling, 2013Co-Authors: Biswajit Sarkar, Sumon SarkarAbstract:This paper expands an Inventory Model for deteriorating items with stock-dependent demand. This Model provides time varying backlogging rate as well as time varying deterioration rate. The aim of this Model is to determine the optimal cycle length of each product such that the expected total cost (holding, shortage, ordering, deterioration and opportunity cost) is minimized. Further, the necessary and sufficient conditions are provided to show the existence and uniqueness of the optimal solution. Lastly, some numerical examples, sensitivity analysis along with graphical representations are shown to illustrate the practical application of the proposed Model.
