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作者：Mak, Ho-Yin; Shen, Zuo-Jun Max
作者单位：Hong Kong University of Science & Technology; University of California System; University of California Berkeley
摘要：The benefits of inventory risk pooling are well known and documented. It has been proven in the literature that the expected costs of a centralized system are increasing in the degree of (positive) dependence of demand in an idealized newsvendor setting. Using the supermodular stochastic order to characterize dependence, we study a general two-tiered supply chain structure, in which both demand and supply yields are random, and prove that the expected costs are increasing in the degrees of pos...
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作者：Secomandi, Nicola; Kekre, Sunder
作者单位：Carnegie Mellon University
摘要：Spot and forward purchases for delivery on the usage date play an important role in matching the supply and the uncertain demand of energy because storage capacity for energy, such as electricity, natural gas, and oil, is limited. Transaction costs tend to be larger in spot than forward energy markets near maturity. Partially procuring supply in the forward market, rather than entirely in the spot market, is thus a potentially valuable real option, which we call the forward procurement option....
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作者：Yom-Tov, Galit B.; Mandelbaum, Avishai
作者单位：Technion Israel Institute of Technology
摘要：We analyze a queueing model that we call Erlang-R, where the R stands for reentrant customers. Erlang-R accommodates customers who return to service several times during their sojourn within the system, and its modeling power is most pronounced in time-varying environments. Indeed, it was motivated by healthcare systems, in which offered-loads vary over time and patients often go through a repetitive service process. Erlang-R helps answer questions such as how many servers (physicians/nurses) ...
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作者：Wan, Zhixi; Beil, Damian R.
作者单位：University of Oregon; University of Michigan System; University of Michigan
摘要：We study a buyer who periodically auctions off short-term supply contracts among her supply base. To mitigate significant cost shocks to procurement, the buyer can diversify her supply base by selecting suppliers from different regions. We find that the buyer's decision to diversify depends on her bid-taker power-that is, her ability to choose the auction mechanism. At one extreme, when the buyer has full bid-taker power and thus can dictatorially implement the optimal mechanism, she always pr...
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作者：Guo, Pengfei; Lindsey, Robin; Zhang, Zhe George
作者单位：Hong Kong Polytechnic University; University of British Columbia; Western Washington University; Simon Fraser University
摘要：We model a two-tier queuing system with free and toll service options as two parallel M/M/1 servers. We solve for the welfare-maximizing toll service capacity and toll subject to the constraint that the toll service cover its costs. If the free and toll services are both used in equilibrium, a larger free-service capacity implies longer expected waiting time for the free service and lower welfare: an analogue to the Downs-Thomson paradox in transportation economics. The paradox is caused by th...
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作者：Singh, Diwas K. C.
作者单位：Emory University
摘要：This paper examines the effect of multitasking on overall worker performance, as measured by processing time, throughput rate, and output quality using microlevel operational data from the field. Specifically, we study the multitasking behavior of physicians in a busy hospital emergency department (ED). By drawing on recent findings in the experimental psychology literature and the nascent work in cognitive neuroscience, we develop several hypotheses for the effect of multitasking on worker pe...
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作者：Newman, Jeffrey P.; Ferguson, Mark E.; Garrow, Laurie A.; Jacobs, Timothy L.
作者单位：University System of Georgia; Georgia Institute of Technology; University of South Carolina System; University of South Carolina Columbia
摘要：We develop a parameter estimation routine for multinomial logit discrete choice models in which one alternative is completely censored, i.e., when one alternative is never observed to have been chosen in the estimation data set. Our method is based on decomposing the log-likelihood function into marginal and conditional components. Our method is computationally efficient, provides consistent parameter estimates, and can easily incorporate price and other product attributes. Simulations based o...
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作者：Deng, Tianhu; Shen, Zuo-Jun Max
作者单位：University of California System; University of California Berkeley
摘要：Several design guidelines and flexibility indices have been developed in the literature to inform the design of flexible,production networks. In this paper, we propose additional flexibility design guidelines for unbalanced networks, where the numbers of plants and products are not equal, by refining the well-known Chaining Guidelines. We study symmetric networks, where all plants have the same capacity and product demands are independent and identically distributed, and focus mainly on the ca...
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作者：Li, Cuihong; Zhang, Fuqiang
作者单位：University of Connecticut; Washington University (WUSTL)
摘要：This paper studies the preorder strategy that a seller may use to sell a perishable. product in an uncertain market with heterogeneous consumers. By accepting preorders, the seller is able to obtain advance demand information for inventory planning and price discriminate the consumers. Given the preorder option, the consumers react strategically by optimizing the timing of purchase. We find that accurate demand information may improve the availability of the product, which undermines the selle...
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作者：Ibrahim, Rouba; L'Ecuyer, Pierre
作者单位：University of London; University College London; Universite de Montreal
摘要：We consider different statistical models for the call arrival process in telephone call centers. We evaluate the forecasting accuracy of those models by describing results from an empirical study analyzing real-life call center data. We test forecasting accuracy using different lead times, ranging from weeks to hours in advance, to mimic real-life challenges faced by call center managers. The models considered are (i) a benchmark fixed-effects model that does not exploit any dependence structu...
