1. A method for running a simulation, comprising: receiving a selection of a device, the device being one of a prober used in wafer testing and a handler used in package testing; receiving at least one parameter for a set of parameters for the simulation; and running the simulation using the set of parameters, to simulate the device being present when the device is not present, the simulated device executing commands received from a controller, the commands being executed as if the device were present, and results from the simulation indicating a performance of the controller.