Receiving an event queue including unprocessed delivery events, each characterized by an event time. Iteratively, until a stopping condition, for an unprocessed event from the queue, setting a simulation time to the earliest event time; processing the unprocessed event; determining at least one simulated performance measure based on characteristics of system agents over the simulation period; and transmitting the determined performance measure for display. Where unprocessed event is a route planning event, processing includes requesting, and receiving, route planning from a shipping system of the near-term delivery system. Processing further comprises identifying events derivative from the unprocessed event, and adding the identified derivative events to the event queue. Processing further comprises updating the status of each agent as a function of derivative events and received route planning information. The updated status is reported to the shipping system, and the technology determines whether the stopping condition obtains.