Partitioning Customers into Service Groups
研究何时以及如何将到达顾客划分为不同服务组，并分配服务器数量，以平衡规模经济与差异化服务时间的收益，适用于服务系统设计者。
We explore the issues of when and how to partition arriving customers into service groups that will be served separately, in a first-come first-served manner, by multiserver service systems having a provision for waiting, and how to assign an appropriate number of servers to each group. We assume that customers can be classified upon arrival, so that different service groups can have different service-time distributions. We provide methodology for quantifying the tradeoff between economies of scale associated with larger systems and the benefit of having customers with shorter service times separated from other customers with longer service times, as is done in service systems with express lines. To properly quantify this tradeoff, it is important to characterize service-time distributions beyond their means. In particular, it is important to also determine the variance of the service-time distribution of each service group. Assuming Poisson arrival processes, we then can model the congestion experienced by each server group as an M/G/squeue with unlimited waiting room. We use previously developed approximations for M/G/sperformance measures to quickly evaluate alternative partitions.