Name __________________________________ Student ID ___________________
THE UNIVERSITY OF WATERLOO
MSCI 432.001/633 Production and Service Operations Management (Winter 2010)
February 11, 2009
Instructor: Benny Mantin
This exam has 10 pages. Please make sure that you have all the pages.
Answers to all questions must be written in the space provided next to the question. Where necessary,
you must show your work. In other words, it should be clear how you arrived at your answer. If you
write the correct answer but it is not clear how you arrived at this answer, you will get no credit.
The points per question, shown below, do not necessarily reflect the relative amounts of time that it will
take to answer each question.
Materials allowed: Calculator.
Candidates found committing any dishonest practices will be immediately dismissed from the
examination, and subject to such discipline as the Faculty or the University may impose. Examples of
dishonest practices include (but are not limited to):
making use of books and other media except those authorized by the examiners
speaking or communicating with other candidates
purposely displaying notes or memoranda to other candidates.
For Instructor Use:
Question No. Marks
1 Name __________________________________ Student ID ___________________
[Processes] Problem 1 (8 points)
Suppose you and your roommate are preparing to start a cookie shop in your apartment. Your
shop will provide fresh cookies to students.
The production process is as follows: (only the 4 main resources mentioned: You, your
roommate, the oven, and the food processor)
Process # Process description Processing Resources Notes
1 Mix all the ingredients 8 min You, food you can process
in a food processor processor up to 2 dozens
2 Spoon out the cookie 3 min your roommate you can only
dough onto a tray process 1 dozen
3 Baking the cookies 10 min oven you can bake only
1 dozen each time
4 Take the tray of 0 min NA
cookies out of the oven
5 Cool cookies 5 min NA
6 Take the cookies off 0 min NA
7 Pack them into a box 3 min your roommate
and accept payment
Each cookie tray can hold 1 dozen cookies.
You have only 1 oven and 1 food processor.
1. Assume that in process #1 you work on one dozen at a time.
a. What is the flow time of the process? [1 point]
b. What is the capacity rate of the process? [1 point] (measure in dozen/hr)
2Name __________________________________ Student ID ___________________
c. Draw the Gantt chart showing the first two dozen for the main four resources. [1 point]
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42
d. How many orders can you fill in one night, assuming that you are open for 4 hours? It is
important to realize that you DONT start working on the first dozen before you open the
shop. [1 point]
a. Sum of the flow time for an order size of 1 dozen cookies is 29 minutes
b. Summary of capacity rates for each resource (oven is process bottleneck)
Resources Capacity Rates (assuming order size = 1 dozen)
You 7.5 dozen / hour (=60/8)
Roommate 10 dozen / hour (=60/6)
Oven 6.6 dozen / hour (=60/10)
Food Processor 7.5 dozen / hour (=60