5) A manager deciding where six departments could be located in a six-room office building has
over 500 possible arrangements.
6) Champion Cooling has just signed a contract to assemble window air conditioners for another
company. The list of tasks, including time requirements and immediate predecessors, follows.
Initially, the plan was to make 300 units in an eight hour day but as the summer months
approach, Champion Cooling finds themselves far behind in total production. They wish to
reconfigure their production line in order to produce maximum output. What should their takt
time be?
Task
Time (min)
Predecessor
Bolt compressor to base
5
None
Install coils and lines
6
Bolt compressor to base
Install fan motor
7
Install coils and lines
Install switch and thermostat
5
Install fan motor
Charge system and test
10
Install switch and thermostat
Cosmetic detailing
7
Charge system and test
A) 5
B) 6
C) 7
D) 10
7) The process design team at a manufacturer has broken an assembly process into eight basic
steps, each with a required time, and predecessor as shown in the table. They work a 7 hour day
and want to produce at a rate of 360 units per day. What should their takt time be?
Task
Time (sec)
Predecessor
A
45
—
B
50
A
C
40
A
D
55
B, C
E
40
D
F
65
D
G
25
E
H
35
F, G
A) 70 seconds
B) 65 seconds
C) 52 seconds
D) 25 seconds
Use this scenario for the following questions.
The process design team at a manufacturer has broken an assembly process into eight basic steps,
each with a required time, and predecessor as shown in the table. There are 8 productive hours
available in a day and the manufacturer wishes to produce 400 units. Use this information to
answer the following questions.
Time (sec)
Predecessor
45
—
50
J
40
J
55
K, L
40
M
65
M
25
N
35
O, P
8) Refer to the scenario above. What is the theoretical minimum number of stations?
A) four
B) five
C) six
D) seven
9) Refer to the scenario above. Operations managers and process engineers design a line that
contains seven stations. What is the percentage of idle time?
A) 21.9%
B) 14.3%
C) 25.6%
D) 17.8%
10) Refer to the scenario above. The manager assigns tasks to workstations and breaks ties using
a longest operation heuristic. That is, if two or three tasks could be assigned to a given station,
the manager assigns the longest task first and then fills in the remaining time at the workstation
as completely as possible. Using this approach, what task(s) would be assigned at the fourth
station?
A) N, P
B) M
C) N, O
D) O, P
Use this scenario for the following questions.
The process design team at a manufacturer has broken an assembly process into eight basic steps,
each with a required time, and predecessor as shown in the table. There are 7.5 productive hours
available in a day and the manufacturer wishes to produce 400 units. Balance the line by
assigning tasks to workstations to fill up as much takt time as possible. Break ties by assigning
the longest task first.
Time (sec)
Predecessor
45
—
50
A
20
A
55
A
15
D
65
D
25
E
35
B, C, F, G
11) Refer to the scenario above. What task(s) should be assigned at the third workstation?
A) B and E
B) D
C) C, E, and G
D) F
12) Refer to the scenario above. Without using more than one worker per station, what is the
maximum output achievable in the 7.5 hour work day?
A) 1000 units
B) 1800 units
C) 1258 units
D) 415 units
13) Refer to the scenario above. The process design team realizes that the potential spike in
demand for this device requires increased output. They elect to add a seventh worker to their
production team at the first station. What is the net effect of adding this worker?
A) Nothing—the output rate does not change.
B) The output rate increases by 20%.
C) The output rate increases by 10%.
D) The output rate increases by 5%.
14) Refer to the scenario above. What is the takt time?
A) 53.3 seconds
B) 67.5 seconds
C) 75.8 seconds
D) 90 seconds
15) Refer to the scenario above. The process engineer calculates the takt time and examines the
task times indicated in the table. He decides to use the minimum cycle time instead and have the
workers leave early each day once they have built 400 units. How much earlier would the
workers leave?
A) 12 minutes and 53.3 seconds
B) 14 minutes and 20 seconds
C) 16 minutes and 40 seconds
D) 18 minutes and 15 seconds
16) Refer to the scenario above. What is the theoretical minimum number of stations that will be
used if the line is balanced using the appropriate takt time?
A) 3
B) 4
C) 5
D) 6
17) Refer to the scenario above. How many workers must be added to increase the output rate to
one unit per minute?
A) 1
B) 2
C) 3
D) 4
18) The table depicts a production line that has been balanced with a takt time of 2 minutes.
What is the percent idle time of this balance?
Workstation
1
2
3
4
5
6
Task
A, B
C
D, E, F
G, H
I
J, K, L
Time (min)
1, 1
1.8
1, 0.5, 0.4
0.9, 0.8
1.8
0.5, 0.5, 0.6
A) 5%
B) 10%
C) 15%
D) Cannot be determined from the information provided.
19) The table depicts a production line that has been balanced with a takt time of 2 minutes.
What is the efficiency of this balance?
Workstation
1
2
3
4
5
6
Task
A, B
C
D, E, F
G, H
I
J, K, L
Time (min)
1, 1
1.8
1, 0.5, 0.4
0.9, 0.8
1.8
0.5, 0.5, 0.6
A) 82.5%
B) 85%
C) 87.5%
D) 90%
20) The table depicts an production line that has been balanced with a takt time of 2 minutes.
Where would you add a worker if you wanted to increase the output rate while keeping six work
stations?
Workstation
1
2
3
4
5
6
Task
A, B
C
D, E, F
G, H
I
J, K, L
Time (min)
1, 1
1.8
1, 0.5, 0.4
0.9, 0.8
1.8
0.5, 0.5, 0.6
A) station 1
B) station 2
C) station 3
D) station 6
21) The table depicts a production line that has been balanced with a takt time of 2 minutes. If
you could hire another six workers, which of these systems would result in the highest output
rate?
Workstation
1
2
3
4
5
6
Task
A, B
C
D, E, F
G, H
I
J, K, L
Time (min)
1, 1
1.8
1, 0.5, 0.4
0.9, 0.8
1.8
0.5, 0.5, 0.6
A) simply duplicating the existing line so you had two lines doing exactly the same thing
B) assigning one worker to each activity and creating a single twelve station production line
C) keeping the existing balance and assigning three workers to stations 1, two workers to station
2, two workers to station 3, one worker to station 4, two workers to station 5, and two workers to
station 6
D) you would be indifferent between alternatives a and b
Use this scenario for the following questions.
With the backyard poultry craze unleashing a tidal wave of municipal code proposals,
Chickenverks is poised to capitalize on the sudden demand for chicken tractors. The portable
henhouses they have designed can be assembled in 10 basic steps, each with a required time and
predecessor as shown in the table. There are 8 productive hours available in a day and the
manufacturer wishes to produce 40 units per hour.
Time (sec)
Predecessor
25
—
35
A
20
A
55
B
45
C, D
15
B
35
C
40
D, E
25
F, G
30
H, J
22) Refer to the scenario above. Balance the line according to the longest operation rule. What is
the assignment for station 2?
A) B, C, F
B) E, H, F
C) C, D
D) D, G
23) Refer to the scenario above. Balance the line according to the longest operation rule. What is
the efficiency of your line balance?
A) 85.66%
B) 90.28%
C) 88.14%
D) 83.88%
24) Refer to the scenario above. What is the theoretical minimum number of stations needed?
A) 3
B) 4
C) 5
D) 6
25) These three tables show the floor layout of 5 departments in an office building, the average
number of daily trips between each pair of offices, and the distance between each pair of offices.
What is the total cost of this layout if there is a $0.50 per foot transportation cost?
Average number of trips between departments
A
B
C
D
E
—
25
15
25
30
—
40
50
35
—
15
15
—
20
—
A
B
D
C
E
Distance between departments (feet)
A
B
C
D
E
—
20
25
40
45
—
5
20
25
—
25
20
—
5
—
A) $460.00
B) $2300.00
C) $3037.50
D) $4785.50
26) The maximum allowable time between completions of successive units on the production
line is the ________.
27) A collection of different departments must be visited by every new student on campus to take
care of registration, housing, books, and other campus services. The placement of these
departments within the university center is an example of a(n) ________ layout.
28) A manufacturer needs to produce 300 coffee pots per 8 hour day. The discrete tasks required
to produce a coffee pot have been identified, timed in seconds, and ordered as indicated in the
table. Sketch the precedence diagram and then assign tasks to workstations on the production
line to achieve the required level of output. Break ties by assigning the longest task first.
Determine the efficiency delay of your line balance.
Task
Time
Predecessors
A
80
—
B
25
A
C
35
A
D
20
B, C
E
50
C
F
70
E
G
45
D
H
25
G
I
15
G
J
40
F, H, I
1
3
4
5
0
5
29) The process design team at a manufacturer has broken an assembly process into eight basic
steps, each with a required time, and predecessor as shown in the table. There are 8 productive
hours available in a day and the manufacturer wishes to produce 400 units using seven
workers—one for each station.
Time (sec)
Predecessor
45
—
50
J
40
J
55
K, L
40
M
65
M
25
N
35
O, P
Balance the line according to the longest operation rule and calculate the percent idle time. Using
the same arrangement of tasks at work stations, what is the greatest output that can be achieved
in an eight-hour day and what is the percent idle time of this design?
30) With the backyard poultry craze unleashing a tidal wave of municipal code proposals,
Chickenverks is poised to capitalize on the sudden demand for chicken tractors. The portable
henhouses they have designed can be assembled in 10 basic steps, each with a required time and
predecessor as shown in the table. There are 8 productive hours available in a day and the
manufacturer wishes to produce 40 units per hour.
Task
Time (sec)
Predecessor
A
25
—
B
35
A
C
20
A
D
55
B
E
45
C, D
F
15
B
G
35
C
H
40
D, E
J
25
F, G
K
30
H, J
Balance the line according to the longest operation rule and calculate the percent idle time. Using
the same arrangement of tasks at work stations, what is the greatest output that can be achieved
in an eight-hour day and what is the percent idle time of this design?
31) Consider any collection of tasks to be assigned to stations in a line balancing exercise. Use
the equation for determining the minimum number of stations to derive an upper bound on the
efficiency of the actual line balance for those same tasks.
32) What is the optimal location for these departments in the floor plan depicted if the
transportation cost is $2 per foot and the departments have a daily number of trips between each
other as shown?
Daily Number of Trips Between Departments
A
B
C
D
E
A
—
20
40
60
80
B
—
10
30
50
C
—
0
15
D
—
5
E
—
Floor Plan
Office Space 1
Office Space 2
Office Space 3
Office Space 4
Office Space 5
Distance Between Offices
Office Space
A
B
C
D
E
1
—
10
20
30
40
2
—
10
20
30
3
—
10
20
4
—
5
5
—