Thank you very much. I was able to create a new model with two servers and have my entities queue up in the server1's input buffer.
Then I tried to do something similar with three servers where I want server1's input buffer to have entities queue up when server3 is busy. I have server2 in between server1 and server3. I set server2's input and output buffers to 0 and set server1 and server2 and paths as described below. Is this correct, to set the in between server's input and output buffers to 0? Everything seems to work as expected and I get a long queue at server1's input buffer. I also used a rate table with many entities going through.
An interesting thing I noticed was that if I change server1 and server2 process times to 3 and 2 seconds respectively and leave server3 process time to the default random.triangular(.1,.2,.3) minutes. I also changed a few selection weights. I barely ever get a queue at server1 input buffer, and when I do, the time in queue is very small. I would have expected a significant queue with the rate table I am using. Does this sound correct? I also ended up getting a Simio error that I ended up sending to Simio, subject [sIMIO EXCEPTION REPORT] from mmashaie. This email includes the model.
Thanks again. Your help has been great.