TITLE: Differentiated Service of Heterogeneous Customers in Overloaded Systems

SPEAKER:  Otis Jennings

ABSTRACT:

Consider a firm whose heterogeneous customer base is sensitive to delays and has demands that exceed the firm’s currently unadjustable processing capacity. One example is an urban emergency department; another is an airport's landing strip during extended intervals of inclement weather. We model such settings as multiclass, overloaded queueing systems with customer abandonment. In such settings, quality of service (QoS) – and indeed whether service takes place at all – is highly dependent upon the order in which customers are processed. We consider two service disciplines. Under FIFO, whereby sufficiently patient customers are served in the order of their arrival, customers receive approximately the same QoS, measured in terms of delay until service initiation, regardless of customer type. We also consider Generalized Round Robin, a family of policies that allows the scheduler to provide differentiated QoS across customer types. This latter policy can be used, for example, to ensure high levels of service for critical customer segments, such as high acuity patients, while not neglecting other segments entirely.