Symbols

Significations

P

System utilization rate

n

Average number of customers in the system (customers who are waiting and customers who are being served)

$\lambda$

Average customer arrival rate (failure rate)

$\mu$

Average customer service throughput (repair rate)

$T_q$

Average waiting time the queue

T

Average waiting time in the system

$P_0$

Probability that there are zero units (customer) in the system

$P_n$

Probability that there are n units (clients) in the system

${\pi }_n\left(t\right)$

Probability that the system is in state $E_n$ at time t