1. A method of simulating responses to request calls in a computer comprising: receiving a call to perform a task by a simulation agent; identifying currently pending requests operable for concurrent processing by the simulation agent; computing, based on a collective load burden of the identified currently pending requests, a completion time for the processing of the received task call including determining a contention period for each interval during which a fixed number of currently pending requests are executing concurrently with the received task; recalculating, based on the received call, the completion time of the currently pending requests; and transmitting a response to the received task call at the recalculated completion time, the computer responsive to the transmitted response for invoking instructions.