Tasks allocation per process in siebel

Hello experts,

How tasks are allocated per process. For example if I have max tasks 400 and MinMTs 10 MaxMTs 20. then how the tasks are getting allocated per process? How does siebel decides that this process has got n number of threads and the next thread needs to be given to the another process. Or is it dependent on memory size? I think it should not be random. Siebel cannot not allocate all the threads to a single process and wait for process crash if it has 10 processes running.

Thanks,

Suresh