Hi Abhishek,
The answer to your question is NO, because it's not a 1-to-1 relationship between DIA workprocess and user. One DIA workprocess can handle multiple users by switching between the context of those users. This is also because one user will not occupy a DIA workprocess 100% all the time, unless it goes to "private mode", which is seldom the case (if it's happened, then the user should probably using BACKGROUND workprocess anyway). So the user will not produce continuous "dialog-steps" in a normal working mode.
The Dispatcher handles all the request of all users and put them in the Dispatcher-queue, and this will be forwarded to a DIA workprocess as soon as it became idle, even in milliseconds, so that's why it can handle hundreds of requests in this queue.
I hope this will help you.
Regards,
Andre