Is it possible to simulate use over some days?

I have struggled with a Mac Pro since this summer. We have had strange problems and I think I have nailed it down to the HDD's.

Now everything is reinstalled with new drives, and I would like to perform a simulation before I leave the computer back to the client.

Is there some kind of simulation software? I'd like to stress the disk, CPU, graphic card etc etc, simulating a normal use.

I know there is Tech Tool Pro, but is there anything else that can do this (I'm not a fan of TTP)?

Thanks,
/andreas