1. A method for allowing simultaneous parameter-driven and deterministic simulation during verification of a hardware design, the method comprising: enabling a plurality of random parameter-driven commands from a random command generator to execute in a simulation environment during verification of the hardware design through a command managing device; enabling a plurality of deterministic commands from a manually-driven testcase port to execute in the simulation environment simultaneously with the plurality of random parameter-driven commands during verification of the hardware design through the command managing device, the plurality of deterministic commands and the plurality of random parameter-driven commands each verify the functionality of the hardware design; enabling a parameter file in signal communication with the command managing device, the parameter file includes random biasing stimuli for modifying or manipulating the plurality of random parameter-driven commands in the simulation environment independently from the plurality of deterministic commands without interrupting the execution of the plurality of deterministic commands; and enabling a testcase file having instructions that are read and decoded by the manually-driven testcase port for generating the deterministic commands.