ISE 403: Homework Lab #1, Spring 2012
Due: Tuesday January 17, 2012 at 11:59pm (submit electronically through
e-mail to firstname.lastname@example.org)
- In the hand simulation of the simple processing system in
Chapter 2, define another time-persistent statistic as the total number of
parts in the system (also called Work-In-Process(WIP)). The total number in
the system includes the parts in the queue and the part(s) in service. Augment
Table 2-2 (in the Arena textbook) to track this as a new global variable and
add new statistical accumulators to get its time average and maximum. Compute
the values of all the statistics at the end (time = 20.0).
Hand in a revised Table 2.2 with the new variable for all parts
(entities) visible. Show calculations needed so that you get partial credit
even if you get the wrong answer.
- In the preceding problem, did you really need to add state
variables and keep track of new accumulators to get the time-average number
of parts in the system? If not, why not? How about the maximum number of parts
in the system?
- There is a very important relationship in systems engineering that relates
WIP and Cycle Time, called Little's Theorem. It states the throughput
is equal to the WIP divided by the Cycle Time. Throughput is parts
per unit time (namely the number of parts produced in the 20 minutes of simulation).
Does Little's Theorem hold in this case?
Show your calculations and state whether Little's Theorem holds.
Submit in one file:
- Revised Table 2.2 (only need to show pertinent columns) with additional columns. Clearly define the additions.
Show how the values are obtained through sample calculations.
- Keep your answers to question 2 brief. Use not more than three sentences
for each question.
- Show calculations to demonstrate whether Little's Theorem holds. In three
or four sentences state why is does or does not hold.