PS scheduling policy

I've just started trying PerfCenter, and I'm interesting in models with processor sharing scheduling policies. I've seen it used in some examples, such as in section 4.2 of the manual. However, when I try it, I get an exception:
resptjava.lang.ClassNotFoundException: perfcenter.simulator.Queue.SchedulingStratergy.PS
Is that scheduling policy implemented?
BTW, I would also like to model arrival rates with a distribution. I tried the following but I got an error.
arate exp(1)
Is it possible to use a distribution for the arrival rate? If I don't specify one as in arate 1, what is the distribution used?



Extremely sorry for this late response.

PS is possibly broken. 

And no, we do not support random arrival rates. The "arate" has to be a number.