how i can use simulink to fix different configurations?

Hi everybody, I have a doubt or a problem, I am not sure. My idea is this: the user has to select a configuration in GUI. For example how many engines he want. If he wants 5 I have to do the simulation with 5, if he wants 6 with six. Always I will have a number of max emngine.

I have think to prepare the simulation with the maximum number of engines and then activate or desactivate thanks to the user option. I do not know if i have explained well, I hope yes.

Thanks