Consider an open queuing system with four facilities A, B, C and D and the data given below

1. a) Draw the queuing network.

2. b) For each server, calculate the probability that it is empty.

3. c) Calculate the expected queue lengths at each server.

4. d) Calculate the average time a customer spends in the system. explain steps, thanks

A B 5 D 7 8 4 External annual rate (customers/hour) 4 3 3 4 Service time (minutes/customer) The transitional probabilities of customers are: A A 0 0.2 0 B 0.1 0 0.5 0 C 0.2 0.3 B D 0 0 0 0 C D 0 0 A B 5 D 7 8 4 External annual rate (customers/hour) 4 3 3 4 Service time (minutes/customer) The transitional probabilities of customers are: A A 0 0.2 0 B 0.1 0 0.5 0 C 0.2 0.3 B D 0 0 0 0 C D 0 0