Sometimes it is possible to write the corresponded model. Then the model can be simulated to receive the performance characteristics. Much depends on that how precise the model is. The keywords are Discrete Event Simulation (DES) and Theory of Queue. It may require some maths.

I wrote a small library called Aivika[1]. Perhaps it might be helpful.

David

[1]http://hackage.haskell.org/package/aivika