Run several Subsystems parallel

Hello,

is it possible to run Subsystems twice or more without an influence on the running subsystem?

I hope i can explain it. I need to scope the movement of a body. The force on the body changes. over time. I need to run the subsystem several times(and how many times is variable).

While the first subsystem is running, i want to start the same subsystem again but seperate from the first subsystem. I want to scope both (or more) ways. As i already said, the Forces on the different Subsystems are not equal.

For example: I have a solid on a conveyor band. The first solid drops on the conveyor. I want to scope that movement. While the first solid is on the conveyor, the second solid drops. Due to acceleration the force on the second solid ist different to the force on the first solid. Both solids have the same differential equation. Only the force is different. I want to scope the way of both solids.

In general i want to start the same subsystem in background again without influence the running subsystems. I don't want to coppy the subsystem, cause i dont know how many solids i got in the end.

I really hope that someone can help me cause this problem makes me crazy :)