Practice Problems: Chapter 10, Human Resources, Job Design, and Work
Measurement
Problem 1:
Develop a Process Chart for making a grilled cheese sandwich.
Problem 2:
Develop an Activity Chart for doing three loads of laundry.
Problem 3:
Develop a Process Chart for changing the oil in an automobile.
Problem 4:
Develop an Activity Chart for writing a term paper.
Problem 5:
Carolyn Barrett, a marketing surveyor, takes an average of 10 minutes to complete a
particular questionnaire. Carolyn’s performance rating (pace) is 110% and there is an
allowance of 15%.
What is the Normal time for completing this questionnaire?
What is the Standard time for completing this questionnaire?
Problem 6:
Tom Leonard, of Leonard, Spitz, and Wareham, takes 3 hours and 25 minutes to write an
end of month report. Tom is rated at 95% (work pace is 95%) and the office has a
personal time allowance of 8%. There is no delay time or fatigue time.
What is the Normal time for writing an end of month report?
What is the Standard time for writing an end of month report?
1
Problem 7:
The two steps in preparing chocolate candy bars are molding and packaging. Personal
fatigue and delay allowances are set at 15%. The molding machine operator is rated at
110% and the packer is rated at 80%. Observed times per batch are given below.
Observed Time in Minutes
Task
1
2
3
4
Molding
26
30
29
31
Packing
45
50
35
30
Determine the Normal and standard times for both tasks.
2
Problem 8:
A work-study sample of a manufacturing activity conducted over a 40-hour period shows
that a worker with an 85% rating produced 12 parts. The worker’s idle time was 10% and
the allowance factor was 12%
Find the Normal and Standard time for this activity.
Problem 9:
Jim and Bob recently time-studied a janitorial task. From a sample of 75 observations,
they computed an average cycle time of 15 minutes with a standard deviation of 2
minutes. Was their sample large enough that one can be 99% confident that the standard
time is within 5% of the true value?
Problem 10:
Consider the following task broken down into 5 MTM elements:
TMUs
Code in MTM Books
Reach to tool box
14.2
R12D
Grasp a tool
3.5
BG1
10.6
AP2
Turn tool
3.5
T45S
Move and focus eyes
13.4
M12B
Separate
pressing
tool
by
What is the total time for the task?
3
ANSWERS
Problem 1:
One possible solution. The level of detail in process charts depends upon the
requirements of the job. Time is often included to aid analysis of value added.
Process Chart
Distance Symbol Process Description
10
Move to cabinet
-
Get loaf of bread
6
Move to counter
-
Open loaf of bread
-
Remove two slices of bread
-
Lay slices on counter-top
-
Close loaf of bread
Move to cabinet
Replace loaf of bread on
shelf
10
Move to refrigerator
Get mustard, package of
ham from refrigerator, and
butter
10
Move to counter
-
Open package of ham
-
Remove two slices of ham
4
-
Close package of ham
-
Open mustard
-
Spread mustard on bread
-
Close mustard
-
Place ham on bread
-
Close sandwich
-
Open butter
-
Spread butter on top slice of
bread
5
Move to stove
-
Get fry pan
-
Turn heat on under fry pan
-
Wait for pan to heat
5
Move to counter
-
Get sandwich & butter
5
Move to stove
-
Place sandwich, butteredside down in pan
-
Butter top slice
-
Close butter
5
Move to counter
5
-
Pick up ham, mustard, and
butter
10
Move to refrigerator
-
Return butter, mustard, and
ham to refrigerator
5
Move to stove
-
Wait for sandwich to brown
on bottom
-
Inspect
-
Flip sandwich
-
Wait for sandwich to brown
on bottom
-
Inspect sandwich
10
Move to serving area
-
Serve sandwich
6
Problem 2:
Time
Operator
Machine
1
Machine
2
Washer
Dryer
Load
clothes
and
detergent
in to
Machine
1
Being
loaded
Idle
Idle
Run
Idle
Remove
clothes
from
Machine
1
Idle
Being
unloaded
Load
clothes
into
Machine
2
Idle
Being
loaded
Load
clothes
and
detergent
into
Machine
1
Being
loaded
Run
Idle
Run
Run
Remove
clothes
from
Machine
2
Idle
Being
unloaded
7
Idle
Hang
clothes
Idle
Problem 3:
One solution might be:
Process Chart for
Changing Oil in Car
Distance Symbol
-
Check that needed filter is
in stock
-
Check that oil is in stock
30
Move to car
Get into car
-
Start engine
-
Idle car to warm engine
-
Drive car onto lift
-
Stop engine
Release hood catch
-
Get out of car
10
Go to lift control
Raise lift
10
Go to toolbox
8
Get wrench
Get container for drained oil
Get rag
10
Walk under lift
-
Wipe around oil drain plug
-
Loosen oil drain plug
-
Position container
-
Remove oil drain plug
-
Drain oil
-
Wipe around oil drain plug
-
Replace oil drain plug
-
Tighten oil drain plug
20
Remove container to
disposal area
15
Move to lift control
Lower lift
Wipe oil from wrench
5
Move to toolbox
Return wrench to tool chest
Get oil filter wrench from
tool chest
9
Get container for drained oil
10
Move to car engine area
-
Raise hood
Find oil filter
-
Loosen oil filter
-
Position container
Remove oil filter
20
Take old filter and container
of drained oil to disposal
area
25
Move to filter stock area
Get new filter
25
Move to car engine area
-
Wipe around filter mount oil
seal
-
Install new filter
-
Tighten new filter
Remove oil filler cap
40
Move to oil stock
Get oil from stock
Move to car engine
compartment
Open oil container; pour in
10
oil filler
Replace oil filler cap
Clean hands
Start engine
Idle engine
Stop engine
Check oil level
Check oil filter seal
Check oil drain plug
Wipe up any spilled oil
Take empty oil containers to
disposal area
Wipe oil from oil filter
wrench
25
Return oil filter wrench to
tool chest
Start engine
Drive car off lift
Park car for owner pickup
Return keys
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Problem 4:
Activity Chart for Writing Term Paper
Time
Operator
Computer
1
Computer
2
Desktop
Library
Develop topic Used for
word
processing
Develop
initial outline
Used for
word
processing
Research
Used for
look-up
and web
search
Flesh out
Used for
outline with
word
information
processing
from research
Evaluate
paper
Final edit
paper
Used for
word
processing
Proof read
paper
Used for
word
processing
Print final
Used for
copy of paper printing
Does this Activity Chart contain enough detail that you could estimate the time it would
take to write the term paper?
12
Problem 5:
Normal time  (total time)(%working on this task)(rating)/(number of units produced)
 (10)(1.00)(1.10)/1  11 minutes
Standard time 
Total Normal time
11
11


 12.9 minutes
1-Allowance factor 1  0.15 .85
Problem 6:
Normal time  (total time)(%working on this task)(rating)/(number of units produced)
 (205 minutes)(1.00)(0.95)/1  194.75 minutes
Standard time 
Total Normal time 194.75 194.75


 211.68 minutes
1-Allowance factor 1  0.08
.92
Problem 7:
Observed Times in Minutes
Task
1
2
3
4
Molding
26
30
29
31
Packing
45
50
35
30
For Molding:
Average for the actual Molding cycle  29 minutes per batch
Normal time  (total time)(% working)(rating)/(number of units produced)
 (29)(1.00)(1.10) /1  31.9 minutes per batch
Standard time  (Normal time)/(1-Allowance)
 31.90 /(1  0.15)  37.5 minutes per batch
For Packing:
Average actual Packing time = 40 minutes
Normal time  (total time)(%working)(rating)/(number of units produced)
13
 (40)(1.00)(.80)  32 minutes per batch
Standard time  (Normal time)/(1-Allowance)
 (32)/(1  0.15)  37.6 minutes
Problem 8:
Average actual time = 40 hours
Normal time  (total time)(%working)(rating)/(number of units produced)
 (40hrs)(0.90)(0.85)/(12)  2.55 hours per part
Standard time  (Normal time)/(1-Allowance)
 2.55 / 0.88  2.90 hours per part
Problem 9:
To find the number of samples required:
 z 
n
 where h is the accuracy desired and z is the confidence level
hx 
2
2
2
 2.575* 2   5.15 
n
 
  47.15 or 48 samples
 0.05*15   .75 
Therefore, the sample size of 75 is sufficient.
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Problem 10:
TMUs
Reach to tool box
Code in MTM Books
14.2
R12D
3.5
BG1
10.6
AP2
3.5
T45S
Move and focus eyes
13.4
M12B
TOTAL
45.2
Grasp a tool
Separate tool by pressing
Turn tool
Remember: 1 TMU = .0006 minutes.
Translating to minutes: 45.2 TMUs * .0006 = .027 minutes
Translating to seconds: .027 minutes * 60 = 1.627 seconds
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