{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

moduleDsolutions

# moduleDsolutions - MODULE D DISCUSSION QUESTIONS 2 The...

This preview shows pages 1–2. Sign up to view the full content.

MODULE D DISCUSSION QUESTIONS 2. The assumptions underlying the standard waiting line or queuing model are: n Arrivals are served on a “first come, first served” (FCFS, or FIFO) basis; and every arrival waits to be served regardless of the length of the line or queue. n All arrivals are independent of preceding arrivals, and the average number of arrivals per unit time (arrival rate) does not change over time. n Arrival rates are described by a Poisson probability distribution, and arrivals come from an infinite or very large source. n Service times vary from one customer to another and are independent of one another, but their average rate is known. n Service times are described by a negative exponential probability distribution. n The effective service rate is faster than the arrival rate. 4. If the service rate is not greater than the arrival rate, the line will increase in length indefinitely. 12. This deals with the interesting issue of the value of waiting time. Some service organizations place a very low value on your time, leading to a good classroom discussion. 15. Supermarkets simply do not have enough space to set up a common line, so they use a separate queue for each checkout station. 16. The cost trade-offs in queuing are waiting cost versus service cost. END-OF-MODULE PROBLEMS D.1 (a) ρ λ μ = = = 40 60 2 3 (b) L q = - ( 29 = - = ( 29 ( 29 μμ 2 2 40 60 60 40 4 3 (c) L s = - = - = 40 60 40 2 (d) W q = - ( 29 = - = = ( 29 40 60 60 40 0 033 2 . hours minutes (e) W s = - = - = = 1 1 60 40 1 20 3 hour minutes = 40/hour, = 60 /hour D.2 (a) = = = 40 90 0 44 44% . (b) L q = - = ( 29 ( 29 40 90 90 40 0 356 2 . (c) L s = - = 40 90 40 0 8 . (d) W q = - = = = ( 29 40 90 90 40 0 0089 0 533 . . hours minutes 32 seconds (e) W s = - = = = 1 90 40 1 50 12 hour minutes 72 seconds .

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 6

moduleDsolutions - MODULE D DISCUSSION QUESTIONS 2 The...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online