Provides facilities to predict the waiting time of contacts. This package defines an interface, {@link umontreal.iro.lecuyer.contactcenters.expdelay.WaitingTimePredictor}, representing a waiting-time predictor. Before a predictor can be used, it must be registered with a router. This registration allows the predictor to register any observer necessary to track system's state. A prediction can be obtained for any contact, whether it is newly-arrived, or is already waiting in a queue.