Some software, as example MatLab, have simulation environments. Simulation environment in MatLab is Simulink. In this environment the process is represented in flow chart, and the networks are the space sate variables and their connections between process units. If you simulated your process by solving directly your equations system by a numerical methods programed by you and co-authors, you must answer this to the reviewer. If you used a simulation software with simulation environment you must define the software and the environment (and the parameters).
It seems as if you tackled a real-world problem, described in words, by means of a simulation tool, without explicitly stating your model, and the precise details of your simulation. In that case no one can judge, whether your approach is, scientifically spoken, a good one.