Author: Shrutivandana Sharma
Publisher:
ISBN:
Category :
Languages : en
Pages : 44
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Book Description
Mismatch between supply and demand when the uncertainty of the demand is high and the supply lead time is relatively long such as seasonal good markets can result in high overstocking and understocking costs. In this paper we propose proactive transshipment as a powerful mechanism to mitigate the mismatch between the supply and demand. We consider a finite horizon multi-period inventory system where in each period two retailers have the options to replenish their inventory from a supplier (if there is any supply) or via proactive transshipment from the other retailer. Each retailer observes non-negative stochastic demand with general distribution during the season and incurs overstocking/understocking costs as well as costs for replenishment and transshipment which may be time dependent. We study a stochastic control problem where the objective is to determine the optimal joint replenishment and proactive transshipment policies so as to minimize the total expected cost over the season. We characterize the structure of the optimal policy, and show that, unlike the known order-up-to level inventory policy, the optimal ordering policy in each period is determined based on two switching curves. Similarly, the optimal transshipment policy is also identified by two switching curves. These four curves together partitions the optimal joint ordering and transshipment polices to eight regions where in each region the optimal policy is an order-up-to-curve policy. We demonstrate that the structure of the optimal policy holds for any known sequence and combination of ordering and proactive transshipment over time. We also show that in the optimal policy retailers try to share the risk of the overstocking and understocking costs.
Author: Youhua Chen
Publisher:
ISBN:
Category :
Languages : en
Pages :
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Book Description
We consider a setting in which inventory plays both promotional and service roles; that is, higher inventories not only improve service levels but also stimulate demand by serving as a promotional tool (e.g., as the result of advertising effect by the enhanced product visibility). Specifically, we study the periodic-review inventory systems in which the demand in each period is uncertain but increases with the inventory level. We investigate the multiperiod model with normal and expediting orders in each period, that is, any shortage will be met through emergency replenishment. Such a model takes the lost sales model as a special case. For the cases without and with fixed order costs, the optimal inventory replenishment policy is shown to be of the base-stock type and of the (s, S) type, respectively.
Author: Jing-Sheng J. Song
Publisher: Edward Elgar Publishing
ISBN: 180037710X
Category : Technology & Engineering
Languages : en
Pages : 565
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Book Description
This comprehensive Handbook provides an overview of state-of-the-art research on quantitative models for inventory management. Despite over half a century’s progress, inventory management remains a challenge, as evidenced by the recent Covid-19 pandemic. With an expanse of world-renowned inventory scholars from major international research universities, this Handbook explores key areas including mathematical modelling, the interplay of inventory decisions and other business decisions and the unique challenges posed to multiple industries.
Author: Lawrence William Robinson
Publisher:
ISBN:
Category : Inventories
Languages : en
Pages : 47
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Book Description
Author: Haolin Feng
Publisher:
ISBN:
Category :
Languages : en
Pages : 30
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Book Description
This paper analyzes optimal replenishment policies that minimize expected discounted cost of multi-product stochastic inventory systems. The distinguishing feature of the multi-product inventory system that we analyze is the existence of correlated demand and joint-replenishment costs across multiple products. While prior literature on multi-product stochastic inventory systems has focused on computation of heuristic policies that decouple the N product problem to N single product problems, our focus is on computing and finding the structure of the optimal policies for multi-product inventory systems, particularly when demand is correlated across products. The problem is formulated as a Markov Decision Process (MDP). A method to compute the optimal policy that uses a moving boundary based policy improvement scheme is proposed. Numerical examples show that the (s, c, d, S) policy closely approximates the optimal policy, and can significantly outperform the (s, c, S), P (s, S) and Q(s, S) policies analyzed in prior literature which assume independent demand.
Author: Narendra Agrawal
Publisher: Springer
ISBN: 1489975624
Category : Business & Economics
Languages : en
Pages : 454
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Book Description
This new edition focuses on three crucial areas of retail supply chain management: (1) empirical studies of retail supply chain practices, (2) assortment and inventory planning and (3) integrating price optimization into retail supply chain decisions. The book has been fully updated, expanding on the distinguishing features of the original, while offering three new chapters on recent topics which reflect areas of great interest and relevance to the academic and professional communities alike - inventory management in the presence of data inaccuracies, retail workforce management, and fast fashion retail strategies. The innovations, lessons for practice, and new technological solutions for managing retail supply chains are important not just in retailing, but offer crucial insights and strategies for the ultimate effective management of supply chains in other industries as well. The retail industry has emerged as a fascinating choice for researchers in the field of supply chain management. It presents a vast array of stimulating challenges that have long provided the context of much of the research in the area of operations research and inventory management. However, in recent years, advances in computing capabilities and information technologies, hyper-competition in the retail industry, emergence of multiple retail formats and distribution channels, an ever increasing trend towards a globally dispersed retail network, and a better understanding of the importance of collaboration in the extended supply chain have led to a surge in academic research on topics in retail supply chain management. Many supply chain innovations (e.g., vendor managed inventory) were first conceived and successfully validated in this industry, and have since been adopted in others. Conversely, many retailers have been quick to adopt cutting edge practices that first originated in other industries. Retail Supply Chain Management: Quantitative Models and Empirical Studies, 2nd Ed. is an attempt to summarize the state of the art in this research, as well as offer a perspective on what new applications may lie ahead.
Author: Leandro Callegari Coelho
Publisher:
ISBN:
Category : Combinatorial optimization
Languages : en
Pages : 0
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Book Description
Author: Michael N. Katehakis
Publisher:
ISBN:
Category :
Languages : en
Pages : 39
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Book Description
Supply contracts are designed to minimize inventory costs or to hedge against undesirable events (e.g., shortages) in the face of demand or supply uncertainty. In particular, replenishment terms stipulated by supply contracts need to be optimized with respect to overall costs, profits, service levels, etc. In this paper, we shall be primarily interested in minimizing an inventory cost function with respect to a constant replenishment rate. Consider a single-product inventory system under continuous review with constant replenishment and compound Poisson demands subject to lost-sales. The system incurs inventory carrying costs and lost-sales penalties, where the carrying cost is a linear function of on-hand inventory and a lost-sales penalty is incurred per lost sale occurrence as a function of lost-sale size. We first derive an integro-differential equation for the expected cumulative cost until and including the first lost-sale occurrence. From this equation, we obtain a closed form expression for the time-average inventory cost, and provide an algorithm for a numerical computation of the optimal replenishment rate that minimizes the aforementioned time-average cost function. In particular, we consider two special cases of lost-sales penalty functions: constant penalty and loss-proportional penalty. We further consider special demand size distributions, such as constant, uniform and Gamma, and take advantage of their functional form to further simplify the optimization algorithm. In particular, for the special case of exponential demand sizes, we exhibit a closed form expression for the optimal replenishment rate and its corresponding cost. Finally, a numerical study is carried out to illustrate the results.
Author: Xiaoying Liang
Publisher: Springer
ISBN: 3319486357
Category : Business & Economics
Languages : en
Pages : 110
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Book Description
This book develops a modeling framework to analyze the problem of inventory management with alternative delivery times. The general context considered here is that a seller replenishes its inventory in fixed intervals and, between replenishments, allocates the limited inventory to satisfy customers who are both price and delivery-time sensitive. On the demand side, customers have heterogeneous delivery-time requirements and choose either spot or late delivery. This theoretical modeling captures the essence of real-world business practices such as the delivery time market segmentation strategy adopted by automobile dealerships in China and many other similar examples. The book focuses on the seller’s optimal inventory replenishment and demand fulfillment policies, and our results provide managerial insights into the merits of flexible delivery-time options. Similar applications such as the group-buying mechanism are also examined. The main mathematical tool used in theoretical analysis is dynamic programming. This book is written for students, researchers, and practitioners in the areas of operations management and industrial engineering who are interested in understanding the rationale of flexible delivery times and designing successful applications.
Author: Jing-Sheng Jeannette Song
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
This paper studies how companies use order-tracking information to more effectively execute their dual-sourcing strategies. We consider dual-sourcing inventory systems under either backlogging or lost-sales assumptions. The normal source consists of a two-stage tandem queue with Erlang distributed processing times at each stage while the emergence source skips the first stage. We show the optimal policy is characterized by two constant thresholds and one emergency-source-state-dependent switching curve. To derive this result, we first reduce the state space by a state transformation; then construct an auxiliary system so that the resulting dynamic program becomes tractable, and show its value function satisfies supermodularity, convexity, and the exchange axiom property that appears to be new to inventory research; finally use a sample-path analysis to show the optimal policy derived from the auxiliary system is also optimal for the original system under a certain condition. Using partial or no order-tracking information, several heuristic policies are developed when the condition fails. We next assess the value of order-tracking information and demonstrate its significant value through numerical studies. Also, the value of full information is more substantial in the backlogging setting than in the lost-sales setting.
