1) 10 points

Located alongside a cobblestoned street in Old City, Old City Photographics (OCP) specializes in the processing of the traditional 35mm negative film, a once dominant photographic medium now in decline due to the popularity of digital photography. OCP offers three packages to their customers. With the standard package, the customer gets a set of 6”x4” prints for $19.99. The deluxe package adds to the standard package a CD-ROM of high resolution scans of the pictures for $29.99. Finally, the $39.99 pro package is similar to the deluxe package in that it comes with a CD-ROM, although the customer gets a contact print rather than a set of prints. (A contact print is an 8”x10” sheet of photographic paper that has all pictures on the roll of film printed next to each other at reduced dimensions and is used as an index.) The workflow for OCP is shown below (s=standard, d=deluxe, p=pro):

OPC pfd

OCP is operated by one person at every station.

i) On average, OCP receive 13 jobs per hour consisted of 44% standard, 37% deluxe and 19% pro. Which of the following statement best describes OCP’s process? Show the work necessary to justify your answer.

a. The process is demand-constrained

b. The process is capacity-constrained and “process film” is the bottleneck

c. The process is capacity-constrained and “scan film” is the bottleneck

d. The process is capacity-constrained and “make 6”x4” prints” is the bottleneck

e. The process is capacity-constrained and “make contact print” is the bottleneck

ii) What is the implied utilization (ratio of workload relative to capacity) at “Scan Film”. Show the work necessary to justify your answer.

a. less than 50%

b. 50% to 60%

c. 60% to 70%

d. 80% to 90%

e. 90% to 100%

f. more than 100%

iii) Fixing the relative proportions of job types, what is the largest number of jobs per hour that OCP can handle? Circle the answer closest to the correct answer. Show the work necessary to justify your answer.

a. 10

b. 11

c. 12

d. 13

e. 14

f. 15

g. 16

h. 17

i. 18

2) 10 points

Imagine US is a startup that offers high definition 3D prenatal ultrasounds for high-end customers. The service process includes five activities that are conducted in the sequence described below. (The time required for each activity is shown in parentheses):

Activity 1: Welcome a patient and explain the procedure. (8 minutes)

Activity 2: Prep the patient (e.g., show them to the room, apply ultrasound gel). (5 minutes)

Activity 3: Take images. (14 minutes)

Activity 4: Analyze images. (12 minutes)

Activity 5: Discuss diagnostic with patient. (16 minutes)

At each location there are employees (servers) S1, S2, and S3. The assignment of tasks to servers is the following:

S1 does Activity 1.

S2 does Activities 2 and 3.

S3 does Activities 4 and Activity 5.

What is the capacity of this process (in customers per hour)?

Suppose 2 patients arrive every hour on average. Ignoring any “start of day” or “end of day” effects, what is the utilization of Server 1 (as a %)?

Now suppose each activity can be assigned to more than one server, each activity can be done by any server and any server can do any set of activities. What is the maximum capacity of the process (in customers per hour)?


3) 10 points

A customer wants delivery to be ensured between 10 am and 2 pm. Your truck leaves the factory at 4 am and the time taken to reach the customer is normally distributed with an average of 8 hrs and a standard deviation of 1 hr.

(a) What is the process capability ratio of the process?

· 0.67

· 0.50

· 1.00

· 2.00

· None of the above

(b) What specific action(s) (in terms of mean and standard deviation targets to be achieved) would you take to improve the ability of the delivery process to be a 6-s process (capability ratio of 2)?

Target mean =

Target standard deviation =

4) 10 points

a) Considerthefollowing two-­?stepprocess.StepAhasaprocessingtimeof1minute perunit,butnosetupisrequired. StepBhasprocessingtimeof0.1minutesperunit,butasetuptimeof9minutesisrequiredperbatch.

Supposeunitsareproduced inbatchesof15(i.e.,aftereachsetof15unitsareproduced, StepBmustincurasetupof9minutes).Whatisthecapacity oftheprocess (inunitsperminute)?

What isthe batch size that maximizesthe flowrate of this process withminimal inventory?Assume thereisampledemand

b) Considerasimpleprocess thatmakestwokindsofshakes:strawberry andbanana.Demandforstrawberryshakesis10gallonsperhour,whiledemandforbananashakes is7.5gallonsperhour.Switching fromonetypeofshaketoanother requires30minutes tocleantheproductionequipmentsothatone flavor does not disruptthe flavor ofthe next shake. Once productionbegins,theprocess canmake30gallonsperhourofeithertypeofshake.Given theseparameters,pleaseevaluate aproductioncyclethatminimizesinventorywhilesatisfyingdemand.

Howmuchshake ( batch size)isproduced intotaloverthecourseofoneproduction cycle(ingallons)?

Howmuchstrawberryshakeisproducedinoneproduction cycle(ingallons)

5) 10 points

Tasty Tim’s is a specialty taco restaurant. The following tasks are required for the successful assembly of a Tasty taco (times are in seconds per taco):

Chop and trim meat – 30

Chop vegetables – 20

Grill meat – 240

Grill vegetables – 180

Prepare toppings

Lettuce -­? 10

Tomato -­? 15

Guacamole -­? 40

Assemble taco

Add meat -­? 5

Add vegetables -­? 5

Add cheese -­? 5

Add toppings -­? 10

Wrap taco -­? 20

During the lunch hour, Tasty Tim’s encounters demand for 120 tacos.

What is the labor content of one of Tasty Tim’s tacos?

What is the takt(cycle) time for Tasty Tim’s taco shop?

How many workers should Tim hire to make tacos? Ignore any effects of idle time or inefficiency due to poor line balancing.

During off-­?peak afternoon hours, demand at Tasty Tim’s drops to 40 tacos each hour. How many employees should Tim schedule to work during the afternoon? Again, ignore any effects of idle time or inefficiency due to poor line balancing.