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We study a new class of inventory control problems, the recruitment stocking problem (RSP), applicable to general recruitment systems and products with limited supplies. Recruitment stocking occurs routinely in many organizations with the goal of identifying qualified candidates rapidly and cost effectively. This activity may take place at multiple sites simultaneously to shorten the recruitment time. Examples include recruiting patients in clinical trials, enlisting personnel in the military, and recruiting customers for product sampling in market testing and promotion. RSP differs from the extant inventory management literature in that it stipulates a finite recruitment target, so that recruitment is terminated as soon as the total number of recruits across all locations reaches that prescribed target. This distinctive feature of RSP calls for the development of new stochastic models to evaluate and optimize system performance. Thus, we present a novel methodology of relaxation and decomposition to characterize the probability distribution of rejections in RSP (number of arrivals to an empty inventory). This method provides a basis for efficient and accurate evaluation of the Type 2 service level and expected recruitment time. We also leverage the attendant computational efficiency to develop optimization algorithms to compute the optimal stocking quantities.

A logical strategy to contain the Covid-19 pandemic is to completely isolate everyone for 2 weeks (the incubation period of the virus). However, such a strategy can have prohibitive economic and social costs and, therefore, will be difficult to implement. At the same time, the current situation is leading to an expanding humanitarian, health and economic crisis. Based on principles of the Theory of Constraints, we propose in this article the “Shutting-down Transmission Of Pandemic” (STOP Covid-19) plan that would reliably contain the pandemic, mitigate its economic consequences, and boost societal confidence. This plan requires the implementation of four strategies over 90 days: (a) stop all international, domestic passenger air and intercity bus/train travel; (b) create administrative zones of about 1 million people; (c) stop all non-emergency cross-zonal travel except for transportation of goods, and (d) deploy an information-driven service value chain to control the spread of the pandemic within a zone.