Informs Annual Meeting Phoenix 2018

INFORMS Phoenix – 2018

TE16

3 - A Model of Queue Scalping Luyi Yang, Johns Hopkins University, 100 International Drive, Baltimore, MD, 21202, United States, Shiliang Cui This paper studies a setting in which a queue scalper enters a waiting line only to sell his position later to future arriving customers. The problem is motivated by the business model of a tech company CallEnQ, which applies the idea of queue scalping to helping professionals spend less time waiting on hold to talk to IRS. We find that a higher demand for the underlying queueing system does not translate to a higher revenue for the queue scalper, which implies that when deciding which queue to enter, a queue scalper should not always target high- demand ones. This result extends to a firm operating any finite number of queue scalpers. n TE16 North Bldg 127B Sustainable and Transparent Supply Chains Sponsored: Manufacturing & Service Oper Mgmt/Sustainable Operations Sponsored Session Chair: Christian Blanco, Ohio State University, Columbus, OH, 43210, United States 1 - Companies’ Contributions to Sustainability through Global Supply Chains Joann de Zegher, Assistant Professor, MIT Sloan, Cambridge, MA, 02142, United States, Tannis Thorlakson, Eric Lambin Companies use a variety of Sustainable Sourcing Practices (SSPs) to address social and environmental challenges in their supply chains. Our current understanding of such SSPs is largely based on theoretical models, literature reviews and case studies. We use a random sample of 450 public companies to study the range of SSPs that companies pursue, addressing the following questions. What SSPs do companies adopt? How many tiers in the supply chain do SSPs cover and to what extent are these SSPs audited? What factors explain the type of SSP a company adopts and are these factors in line with theoretical predictions? This research helps direct the research agenda in sustainable supply chain management. 2 - Motivating Supplier Social Responsibility under Incomplete Visibility Leon Valdes, University of Pittsburgh, Joseph M. Katz Graduate School of Business, 119B Mervis Hall, Pittsburgh, PA, 15260, United States, Tim Kraft, Yanchong Zheng We study a manufacturer’s decisions when the social responsibility (SR) performance of her supplier cannot be perfectly observed. Only the supplier can directly impact SR; the manufacturer can: (i) invest in the supplier’s capabilities to improve SR; and (ii) disclose SR information to consumers. A third party may disclose the true level of SR, which can lead to a penalty for the manufacturer. Our results show that greater visibility helps the manufacturer to better tailor her investment. In addition, disclosing SR leads to an improvement in supplier SR practices, but this disclosure is least likely when the supplier has average (not too low and not too high) SR practices. 3 - Can Brands Claim Ignorance? Unauthorized Subcontracting in Apparel Supply Chains Anna Saez de Tejada Cuenca, UCLA Anderson School of Management, 110 Westwood Plaza, B-501, Los Angeles, CA, 90095, United States, Felipe Caro, Leonard Lane The collapse of the Rana Plaza building in Bangladesh brought into focus the poor safety conditions faced by many workers in the apparel industry. A common way in which safety and environmental standards are violated is through unauthorized subcontracting. We analyze empirically some factors that can lead suppliers to outsource their production to third parties without their retailers’ knowledge. We use data provided by a supply chain manager that consists of over 30,000 orders, including 36% of subcontracted ones. Our results provide managerial insights to retailers on what factory and order characteristics increase the probability of unauthorized subcontracting, and how it can be prevented.

customers to be served by servers from a non-primary pool (determined through the flexible design) with a reduced service rate to capture the effect of off- placement. 2 - Design and Pricing of Discretionary Service Lines Laurens G. Debo, Dartmouth College, 100 Tuck Hall, Hanover, NH, 03755, United States, Cuihong Li We discuss the optimal offering of a menu of discretionary services, for which longer processing times yield higher quality, but also create more system congestion. We show that prioritizing short services increases the breadth of the menu and that prices may be non-monotone in duration. 3 - Queueing and Learning Demand systems used in service operations often assume that system parameters that affect user decisions, e.g., to join a system or purchase a service, are known or communicated to the market. In practical settings this need not be the case, but users may still form estimates of these parameters through their own observations. We study the effect of observational learning on user behavior and equilibrium performance in a congested queueing model where delay-sensitive customers with no a priori knowledge of the service rate, join the system and observe their progress through the queue in order to learn the system’s service rate, estimate remaining waiting times, and make abandonment decisions. 4 - On Personalized Scheduling Disciplines in Queueing Systems: Does Knowing your Customer Matter? Seyedmorteza Emadi, University of North Carolina-Chapel Hill, 221 Tremont Circle, Chapel Hill, NC, 27516, United States, Rouba Ibrahim, Saravanan Kesavan The paradigm of personalized queues is becoming increasingly relevant with the availability of customer-speci?c data in practice. In this work, we focus on the implementation of scheduling policies exploiting individual customer service-time information. By analyzing data from a call center, we quantify the improvement in predictive accuracy resulting from exploiting individual customer history to predict future service times. We quantify the operational impact of using those improved predictions in the scheduling of customers through both direct analysis and a numerical study. Strategic Queueing in Service Operations Sponsored: Manufacturing & Service Oper Mgmt/Service Operations Sponsored Session Chair: Jianfu Wang, Nanyang Business School, Nanyang Technological University, Singapore, 639798, Singapore Co-Chair: Shrutivandana Sharma, Singapore University of Technology and Design, 20 Dover Drive, Singapore, 138682, Singapore 1 - Evaluating the First-mover’s Advantage in Announcing Real-time Delay Information Siddharth Prakash Singh, Carnegie Mellon University, Tepper School of Business, 5000 Fobes Avenue, Pittsburgh, PA, 15213, United States, Mohammad Delasay, Alan Scheller-Wolf Advances in internet-based technology have enabled service providers to disseminate real-time delay estimates to customers who are strategic and delay- sensitive. In a market with two service providers who compete for market share, we investigate whether one of the service providers (the technology leader L) should begin to announce her real-time delay information, knowing her competitor (the follower F) could opt to respond. We cast this leader-follower setting as a sequential queueing game. We find that L’s delay announcements improve, in equilibrium, her market share when she is not the higher-capacity service provider; otherwise, initiating delay announcements erodes her market share. 2 - Queueing Design when Customers Can Balk: Pooled or Dedicated? Nur Sunar, UNC, 1604 Village Crossing Drive, Chapel Hill, NC, 27517, United States, Yichen Tu, Serhan Ziya It is generally accepted that operating with a combined (i.e., pooled) queue rather than separate (i.e., dedicated) queues is beneficial mainly because pooling reduces average throughput time in a system. We consider a multi-server queueing system that can be run as a pooled or a dedicated system. Unlike the pooling literature, in our paper, customers are rational, i.e., they decide to join or balk based on queue length information upon arrival. We prove that, in contrast to the general understanding, the dedicated system can result in strictly smaller average throughput time, and strictly larger social welfare than the pooled system; performance degradation due to pooling can be significant. n TE15 North Bldg 127A Costis Maglaras, Columbia University, Graduate School of Business, 3022 Broadway Avenue, New York, NY, 10027, United States, John J. Yao, Assaf Zeevi

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