In this paper we examine contracts to coordinate the capacity decision of a vendor who has been hired by a client to provide call center support. We consider a variety of contracts, all based on our observations of contracts used by one large vendor. We examine the role of different contract...

This paper studies service systems with gatekeepers who diagnose a customer problem and then either refer the customer to an expert or attempt treatment. The probability of successful treatment by a gatekeeper decreases as the problem's complexity increases. We determine the optimal staffing...

We examine how operational changes in customer flows in retail stores affect the rate of COVID-19 transmission. We combine a model of customer movement with two models of disease transmission: direct exposure when two customers are in close proximity and wake exposure when one customer is in the...

The majority of COVID-19 vaccines currently available are typically administered in two doses, with a prescribed number of weeks separating the two doses. Because of uncertainty in vaccine supply, many vaccination managers have saved doses in inventory to ensure on-time second doses. However,...

This paper studies outsourcing decisions for a two-level service process in which the first level serves as a gatekeeper for a second level of experts. The objective of the system operator (the client) is to minimize the sum of staffing costs, customer waiting costs, and mistreatment costs due...

Many service systems use case managers, servers who are assigned multiple customers and have frequent, repeated interactions with each customer until the customer’s service is completed. Examples may be found in health care (emergency department physicians), contact centers (agents handling...

We describe an approximation procedure to estimate the performance of a queueing system with two types of customers and two server categories. Specialized servers can process only one customer type, while flexible servers handle both types. The procedure divides the system's state space into...

Major airlines are selling increasing numbers of interline itineraries, in which flights operated by two or more airlines are combined and sold together. One reason for this increase is the rapid growth of airline alliances, which promote the purchase of interline itineraries and therefore...