1.Information Sharing in a Make-to-stock Supply Chain
Abstract: This paper addresses how different coordination mechanisms affect the information sharing behavior in a supply chain. We study information sharing in a make-to-stock supply chain under wholesale contract and revenue sharing contract. Under wholesale contract, we show that information sharing is always beneficial to the supplier and identify the conditions ensuring that information sharing is beneficial to the retailer. Under revenue sharing contract, information sharing is beneficial to the supplier, the retailer and the supply chain. This research indicates that whether sharing the demand information is beneficial depends on the coordination mechanism and parameters.
Journal of Industrial and Management Optimization, 2014.(SCI Index)
2.Postponed Product Differentiation with Demand Information Update
Abstract: This paper studies the problem of how to coordinate postponed product differentiation and forecast update to improve manufacturing efficiency. We consider a two-stage model of multiple products with a common component. In stage 1, the manager obtains a prior demand distribution of each product and decides the production quantity of the common component. In stage 2, the demand forecast is updated and the common component is differentiated into various final products. Then the final demand of each product is realized and inventory leftover (shortage) is assessed. We use stochastic programming to model this problem, and propose an optimal bundle-type algorithm to solve it. Furthermore, we develop some simple and effective approximation algorithms for several special cases. Extensive numerical experiments are conducted to show the effectiveness of the approximation algorithms, to compare the performance between the traditional production model and the postponement production model, and to examine the impact of parameters on the performances of the two systems.
International Journal of Production Economics, 2013.(SCI Index)
3.Coordination of Information Sharing in a Supply Chain
Abstract: In this paper, we study information sharing in a supply chain consisting of one supplier and one retailer, in which both the supplier and the retailer possess partial information on the demand. Under the single price contract, we show that whether a firm reveals its private information depends on the quality (variance) and the correlation of the two firms' information and the other firm's information revelation behavior. For the case that one firm (the retailer or the supplier) has complete information on the demand, the equilibrium is that the firm with complete information conceals its information and another reveals its information. Finally, we show that revenue sharing contract is coordinative, which ensures that both firms share their information completely and the retailer chooses the sale quantity which maximizes the total profit of the supply chain. This study shows that the members in a supply chain must sign coordinative contract in order to ensure that they share their information.
International Journal of Production Economics, 2013.(SCI Index)
4.Integrated Decision on Pricing, Promotion and Inventory Management
Abstract: Firms often utilize promotion (such as coupons, advertisements, recruitment of excellent salespeople, and leafleting etc.) and dynamic adjustment of price to manage customers as well as proper production/inventory plan to satisfy the customers to get maximal profit in a firm. The decision on promotion and pricing and the decision on production/ inventory must support each other This paper addresses coordinated decision on pricing, promotion(non-price promotion) and inventory management. Specifically, we study a single item, periodic review model. The demand function is a linear demand function in which the market scale can be affected by the promotion conducted in that period. Unsatisfied demands are fully backlogged. We characterize the structure of the optimal policy that simultaneously determines the price, the promotion and the ordering quantity to maximize the total discounted profit with finite and infinite period problems. We show that the optimal replenishment policy is the quasi base stock list price target
promotion policy, i.e., there exist a critical inventory level, a list price and a target promotion such that it is optimal to order up to the critical level, charge the list price and conduct the target promotion when the initial inventory is below the critical level and order nothing, conduct a higher promotion and charge a proper price to increase the demand otherwise. We also prove that the expected demand and the optimal promotion are increasing in the inventory, and price and promotion are complementary. Then we extend the problem to the case with capacity constraint. We show that the modified quasi base stock list price target promotion policy is optimal. For the joint decision problem on pricing, promotion and inventory control with positive fixed setup cost, we show that
the optimal policy is (s, S, p, e) policy. That is, there exist two critical inventory levels st and St (st ≤ St), a list price pt and a target promotion et in period t such that order up to St, charge price pt and conduct promotion et when the initial inventory is less than st and order nothing, charge a proper price and conduct a proper promotion otherwise.
Asian-Pacific Journal of Operations Research, 2012.(SCI Index)
5.Coordinated Pricing and Inventory Control Problems with Capacity Constraints and Fixed Ordering Cost
Abstract: This article addresses a single-item, finite-horizon, periodic-review coordinated decision model on pricing and inventory control with capacity constraints and fixed ordering cost. Demands in different periods are random and independent of each other, and their distributions depend on the price in the current period. Each period's stochastic demand function is the additive demand model. Pricing and ordering decisions are made at the beginning of each period, and all shortages are backlogged. The objective is to find an optimal policy that maximizes the total expected discounted profit. We show that the profit-to-go function is strongly CK-concave, and the optimal policy has an (s,S,P) -like structure.
Naval Research Logistics, 2012.(SCI Index)
6.Supplier Selection and Purchase Problem with Fixed Cost and Constrained Order Quantities under Stochastic Demand
Abstract: This paper addresses a supplier selection and purchase problem under stochastic demand. In particular, a buyer firm (manufacturer or retailer) wants to procure a product from a group of potential suppliers, which may quote different prices and have restriction on minimum and maximum order sizes, to satisfy the uncertain demand. In addition to holding and shortage costs, a fixed cost is incurred for the buyer when a potential supplier is selected. The objective is to select suppliers and to allocate the ordering quantity properly among the selected suppliers to minimize the total cost, including selection, purchase, holding and shortage costs. The problem is modeled as a Mixed Integer Programming (MIP). Properties of the problem are explored and a branch-bound algorithm is proposed for it. Also, a simple algorithm for the subproblem is proposed based on its special structure. Numerical experiments are conducted to evaluate the performance of the algorithm and some managerial insights are obtained.
International Journal Production Economics, 2011.(SCI Index)
7.Newsboy Problem under Knightian Uncertainty
Abstract: In this paper, we consider newsboy problem under Knightian uncertainty. That is, we assume that the uncertainty of demand is Knightian uncertainty. We use info-gap uncertainty to model the uncertainty of the demand. The objective is to study the robustness of the optimal policy. We first assume that the price is exogenous and then the price is determined endogenously and is a decision variable. We study the optimal policies for the inventory control system with and without price setting under Knightian uncertainty and their robustness. We show that the relative robustness of the sole inventory system and the joint pricing and inventory control with multiplicative demand function to profit loss are the same and higher than that of the joint pricing and inventory control with additive demand function.
2011 8th International Conference on Services Systems and Services Management, 2011.(ISTP Index)
8.Coordinating Pricing and Inventory Decisions in a Bounded Production System with Uncertain Yield
Abstract: Most inventory researches assume that production level can fluctuate arbitrarily. However, large fluctuation of the production level in many firms may be much costly. This paper addresses the coordinating pricing and inventory control problem in a bounded production system with uncertain yield, in which the production level is constrained between a maximum and minimum level in each period and the price can be adjusted dynamically. We show that the optimal policy is the interval base-stock-list-price policy. Also, we study the impact of the production bounds and uncertainty of the yield on the production system. Numerical experiments are also performed to study the impact of parameters on the system.
Journal of Systems Science and Systems Engineering, 2010.(SCI Index)
9.Externality of Contracts on Supply Chains with Two Suppliers and a Common Retailer
Abstract: This paper addresses the impact of different contracts on supply chains with different suppliers and a common retailer. Especially, we consider a supply chain system consists of a retailer and two suppliers (supplier1 and supplier 2 and the supply chain consisting of supplier ( and the retailer is named supply chain ( for simplicity) in which supplier 1 and the retailer agree to simple wholesale price contract and supplier 2 and the retailer agree to revenue sharing contract. The products provided by these two suppliers are complement or substitution. We study the external effect of these two contracts. The main findings of this study are as follows: When the two products are not independent, the design of a coordinative contract depends the stocking quantity of another product; Under the same external conditions, both simple wholesale price contract and revenue sharing contract perform the same when the products are complement, and revenue sharing contract performs better than simple wholesale price contract when the products are substitutive or independent; we can also design a wholesale price contract and a revenue sharing contract which coordinate these two supply chains simultaneously when the products are complement. Moreover, we consider the case that the demand depends on costly retailer's effort. We show that wholesale price contract always distorts the retailer's decision on effort in supply chain 1 and we can design a revenue sharing contract coordinating supply chain 2. Whether wholesale price contract or revenue sharing contract is more incentive to encourage retailer's promotion effort depends on the problem and contract parameters. These findings are different from the well known properties of these two contracts in a supply chain consisting of 1-supplier and 1-retailer. As retailers always sell multi-items in reality, we believe that our findings could help managers manage channels efficiently.
Journal of Industrialand Management Optimization, 2010.(SCI Index)
10.A Multi-period Pricing and Inventory Control Model
Abstract: The authors analyze a finite horizon, single product, period review model in which pricing and inventory decisions are made simultaneously. Demands in different periods are random variables that are independent of each other and their distributions depend on the product price. Pricing and ordering decisions are made at the beginning of each period and all shortage are backlogged. Ordering cost is a convex function of the amount ordered. The objective is to find an inventory and pricing policy maximizing expected discounted profit over the finite horizon. The authors characterize the structure of the optimal combined pricing and inventory strategy for this model. Moreover, the authors demonstrate how the profit-to-go function, order up to level, reorder point and optimal price change with respect to state and time.
Journal of Systems Science & Complexity, 2010.(SCI Index)
11.Coordinating Pricing and Inventory Control in a Fluctuating Environment
Abstract: This paper addresses the simultaneous determination of pricing and inventory replenishment strategies under a fluctuating environment. Specifically, we analyze the single item, periodic review model. The demand consists of two parts: the deterministic component, which is influenced by the price, and the stochastic component (perturbation). The distribution of the stochastic component is determined by the current state of an exogenous Markov chain. The price that is charged in any given period can be specified dynamically. A replenishment order may be placed at the beginning of some or all of the periods, and stockouts are fully backlogged. Ordering costs that are lower semicontinuous, and inventory/backlog (or surplus) costs that are continuous with polynomial growth. Finite-horizon and infinite-horizon problems are addressed. Existence of optimal policies is established. Furthermore, optimality of (s,S,p)-type policies is proved when the ordering cost consists of fixed and proportional cost components and the surplus cost (these costs are all state-dependent) is convex.
12.Capacitated Facility Location Problem with Freight Cost Discount
Abstract: In reality, unit shipment cost is a decreasing function in shipment volume because of economics of scale. In this paper, we extend the capacitated facility location problem (CFLP) considering discounted freight cost. We formulate this problem as a mixed integer linear problem (MILP), and minimize the total cost including setup costs for opening the facilities and transportation costs with freight cost discount. Based on the special structure of the MILP, a Benders decomposition algorithm is proposed to solve it.
IEEE 2010 7th International Conference on Service Sciences and Service Management, 2010.(ISTP Index)
13.Inventory Control Problem with Freight Cost and Stochastic Demand
Abstract: This paper generalizes the standard newsboy model to the case including freight cost, in which the capacity of one container is the limit and the freight cost is proportional to the number of the containers used. We show that the optimal ordering quantity is either the newsboy solution or some multiple of the container’s capacity. We also propose an algorithm to compute the optimal policy. Furthermore, we generalize these results to the case in which the inventory and the price are determined jointly with emergency purchase.
Operations Research Letters, 2009.(SCI Index)
14.Several Multi-criteria Programming Methods for Classification
Abstract: In this paper, we propose a general optimization-based model for classification. Then we show that some well-known optimization-based methods for classification, which were developed by Shi et al. [Data mining in credit card portfolio management: a multiple criteria decision making approac. In: Koksalan M, Zionts S, editors. Multiple criteria decision making in the new millennium. Berlin: Springer; 2001. p. 427–36] and Freed and Glover [A linear programming approach to the discriminant problem. Decision Sciences 1981; 12: 68–79; Simple but powerful goal programming models for discriminant problems. European Journal of Operational Research 1981; 7: 44–60], are special cases of our model. Moreover, three new models, MCQP (multi-criteria indefinite quadratic programming), MCCQP (multi-criteria concave quadratic programming) and MCVQP (multi-criteria convex programming), are developed based on the general model. We also propose algorithms for MCQP and MCCQP, respectively. Then we apply these models to three real-life problems: credit card accounts, VIP mail-box and social endowment insurance classification. Extensive experiments are done to compare the efficiency of these methods.