Description
1. A librarian at a college library, on an average, could process 18 students during one hour. On an average, a student arrives to her at every 4 minutes. Assume it is a single-server waiting line model.
(a) Determine the mean arrival rate and the mean service rate.
(b) Determine the probability that a student will have an empty queue.
(c) Determine the probability that 2 students are in the queuing system.
(d) Determine the average number of students in the queue and the average number of students in the system.
(e) Determine the average waiting time in the queue and the average total time in the system for a student.
(f) Find the utilization factor of the librarian.
In Question 1, suppose the librarian can be
replaced by a specialist, who must be paid $32 per hour whereas the current librarian
is paid $22 per hour. The specialist can process 22 students in one hour. If a student’s
time is considered to be worth $10 per hour, is it worth to replace the current
librarian with the specialist?
Explanation & Answer
Hi there!Attached please find the complete solution in a Word document. All formulae have been typed out and completed.The Excel document contains all of the work that was used to generate the information :)Thanks again!Selenica
Arrival rate (l)
Service rate (m)
Number of servers
Server cost $/time)
Waiting cost ($/time)
0,25
0,3
1
22
10
Probabilities
Number
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Results
Average server utilization(r)
Average number of customers in the queue(L q)
Average number of customers in the system(L)
Average waiting time in the queue(Wq)
Average time in the system(W)
Probability (% of time) system is empty (P0)
Cost - based on waiting
Cost - based on system
Probability Cumulative Probability
0,166667
0,166667
0,138889
0,305556
0,115741
0,421296
0,096451
0,517747
0,080376
0,598122
0,066980
0,665102
0,055816
0,720918
0,046514
0,767...