Let's consider the common waiting system as an example were one needs approximate models, including the Monte Carlo.
By common waiting we define a system serving calls of different type. We represent them as a call-vector
. Different calls are served by different servers. However, there are
of common waiting places. There are no such simple formulas as (2.15) and (2.16) in this case.
Therefore we consider two approximate solutions: an analytical model, called as the "reservation" model, and the Monte Carlo one.