O.M. 2nd EXAM UNDERGRAD

3rd
EDITION
STATE l UNIVERSITY
Applied Management Science for Decision Making, 2e © 2014 Pearson Learning Solutions
Philip A. Vaccaro , PhD
Multiple Choice
1. Intermittent flow operations:
a.
b.
c.
d.
involve close management of workers.
generate a high product mix.
have few schedule changes.
have high turnovers of raw materials and
work-in-process inventories.
2. Continuous flow operations:
a.
b.
c.
d.
utilize general-purpose equipment.
are capital-intensive operations.
have unpredictable material flows.
have work centers grouped together
by function ( department ).
Multiple Choice
3. Repetitive manufacturing:
a.
b.
c.
d.
assembles pre-made parts into finished goods.
produces one basic product with minor variations.
Is characterized by very low equipment utilization.
utilizes highly trained, flexible labor.
4. Design capacity is:
a. sustainable capacity.
b. capacity dictated by the firm’s built-in organizational
constraints.
c. theoretical capacity.
d. actual output.
Multiple Choice
5.
The stepping-stone method is used to:
a. obtain an initial ( 1st ) solution.
b. balance source supply and destination demand.
c. evaluate occupied cells ( routes ) for possible cost
reductions.
d. evaluate empty cells ( routes ) for possible
cost reductions.
6.
Which of the following statements is true?
a. evaluation paths selected must be as short as possible.
b. evaluation paths may contain diagonal movements.
c. occupied cells may not be bypassed if turning movements are desired.
d. all occupied cells of each solution must be evaluated.
Multiple Choice
7. The intent of the load-distance model is:
a. to minimize the number of workers.
b. to minimize idle time per cycle.
c. to minimize materials and/or information movement
costs within a process layout.
d. none of the above.
8. Which of the statements about line-balancing is true?
a. if a precedence relationship exists between tasks A and B,
they cannot be assigned to the same work station.
b. if a line’s balance delay factor is maximized, its efficiency
is maximized.
c. the theoretical minimum number of work stations can never
be achieved, hence the name “theoretical”.
d. if the cycle time is reduced, productivity will increase.
Multiple Choice
9. Hybrid or combination layouts:
a. were developed by Henry Gantt in 1901.
b. require the use of work-in-process inventories between
the pure layouts.
c. are similar in their characteristics to fixed-position layouts.
d. are rarely encountered in industry.
10. Which of the following statements is true?
a. line-balancing attempts to eliminate bottleneck tasks via product
redesign and better worker training.
b. the efficiency of an assembly line cannot be improved by selecting
a different task assignment heuristic for the line-balancing process.
c. an assembly line is perfectly balanced when there are an equal
number of tasks in each work station.
d. “efficiency” is defined as an assembly line’s ability to meet
desired daily output.
Multiple Choice
11. The Behavioral School approach to job design which
attempts to make a worker a “co-manager” is:
a.
b.
c.
d.
job enlargement.
job enhancement.
job rotation.
job enrichment.
12. The 5 categories of activities ( operation, transportation,
inspection, delay, and storage ) are used in which of the
following methods of process analysis?
a.
b.
c.
d.
gang chart.
simo chart.
multiple activity chart.
motion economy chart.
Multiple Choice
13. The procedure that involves performance ratings
and allowance factors is :
a.
b.
c.
d.
historical experience.
work sampling.
direct time study.
pre-determined time study.
True or False
14. In cross-docking, labeled and presorted loads are received
directly at the warehouse dock for immediate re-routing.
TRUE
FALSE
15. A job shop helps a firm follow a differentiation marketing
strategy.
TRUE
FALSE
16. Group technology layouts are used to convert assembly
lines into job shops.
TRUE
FALSE
True or False
17. The Northwest-Corner technique produces a deliberate costefficient solution for the transportation algorithm.
TRUE
FALSE
18. Work sampling is widely used to analyze repetitive jobs.
TRUE
FALSE
19. The maximum allowable cycle time guarantees that the firm
will meet its daily production quota.
TRUE
FALSE
True or False
20. The direct time study method makes allowances for unscheduled
interruptions, unusual delays, and unusual mistakes on the part
of the worker.
TRUE
21.
FALSE
In the transportation problem, the number of cells in an evaluation path should always be an odd number such as “5”, ”7”,
or “9”.
TRUE
FALSE
22. One of the limitations of the transportation algorithm is that it
cannot minimize shipping costs between two levels of the
supply chain.
TRUE
FALSE
True or False
Nine ( 9 ) welders who perform the identical short-cycle job were observed by
a time and motion engineer over six ( 6 ) cycles each. The total time recorded
was three-hundred-ten ( 310 ) minutes.
The performance rating for a particular welder was established at ninety-two
percent ( 92% ). Additionally, each welder is granted a twelve percent ( 12% )
allowance for personal needs, fatigue, and routine delays.
23. The observed time ( OT ) for this job is 5.833 minutes.
TRUE
FALSE
24. The normal time ( NT ) for the selected welder ≈ 5.280 minutes.
TRUE
FALSE
25. The standard time ( ST ) for the selected welder ≈ 6.000 minutes.
TRUE
FALSE
True or False
Nine ( 9 ) welders who perform the identical short-cycle job were observed by
a time and motion engineer over six ( 6 ) cycles each. The total time recorded
was three-hundred-ten ( 310 ) minutes.
The performance rating for a particular welder was established at ninety-two
percent ( 92% ). Additionally, each welder is granted a twelve percent ( 12% )
allowance for personal needs, fatigue, and routine delays.
observed time ( OT ) = 310 / ( 9 x 6 ) = 5.7407
normal time ( NT ) = 5.7407 x .92 = 5.2814
standard time ( ST ) = 5.284 / ( 1 - .12 ) = 6.0045
Assembly Line Balancing Problem
Problem 1
A firm desires to achieve a production rate of
seventy-five ( 75 ) units per six ( 6 ) hour day,
utilizing an assembly line.
The table below lists the nine ( 9 ) tasks that
must be performed to produce each unit as
well as the sequence in which they must be
performed.
Assembly Line Balancing Problem
Task
Predecessor ( s )
Time ( in seconds )
A
B
C
D
none
A
A
C
60
60
120
60
E
F
G
C
C
D,E,F
180
60
60
H
I
B
G,H
120
60
Assembly Line Balancing Problem
For your convenience, a precedence relationship ( s ) diagram has been
included below. The tasks are shown as nodes. The sequence requirements are shown by arrows. The required standard task times are shown
within each task’s respective node:
B
60
H
120
D
60
A
60
I
60
C
120
E
180
F
60
G
60
Assembly Line Balancing Problem
REQUIREMENT:
Problem 1
A. The maximum allowable cycle time.
B. The theoretical minimum number of work stations.
C. The balanced assembly line under the longest operating
time ( LOT ) assignment heuristic.
D. The balance delay factor of the assembly line.
E. The efficiency of the assembly line.
Assembly Line Balancing Problem
Maximum
Allowable
Cycle Time
Total available production time
=
Daily production quota
6 hours x 60 x 60
=
75 units
21,600 seconds
=
75 units
=
288 seconds
Multiple Choice
26. In problem one, the maximum allowable cycle
time is:
a.
b.
c.
d.
288 seconds.
315 seconds.
348 seconds.
384 seconds.
Assembly Line Balancing Problem
Theoretical
Minimum
=
Number of
Work Stations
Total time to produce one unit
Maximum allowable cycle time
780 seconds
= 2.7083 ≈ 3
=
288 seconds
Multiple Choice
27. In problem one, the theoretical number of
work stations is:
a.
b.
c.
d.
1
2
3
4
Assembly Line Balancing Problem
CANDIDATE(S) FOR TASK 1 IN STATION 1
B
60
H
120
D
60
A
60
I
60
C
120
E
180
F
60
G
60
Assembly Line Balancing Problem
Balancing under the LOT assignment heuristic
Cycle time
288
seconds
288
seconds
288
seconds
864
seconds
Station
1
Station
2
Station
3
Total
A (60)
Production Time
Idle Time
Assembly Line Balancing Problem
CANDIDATE(S) FOR TASK 2 IN STATION 1
B
60
X
H
120
D
60
A
60
I
60
C
120
E
180
F
60
G
60
Assembly Line Balancing Problem
Balancing under the LOT assignment heuristic
Cycle time
288
seconds
288
seconds
288
seconds
864
seconds
Station
1
Station
2
Station
3
Total
A (60)
C (120)
Production Time
Idle Time
Assembly Line Balancing Problem
CANDIDATE(S) FOR TASK 3 IN STATION 1
B
60
X
A
60
H
120
D
60
X
C
120
I
60
E
180
F
60
G
60
Assembly Line Balancing Problem
Balancing under the LOT assignment heuristic
Cycle time
288
seconds
288
seconds
288
seconds
864
seconds
Station
1
Station
2
Station
3
Total
A (60)
C (120)
B (60)
Production Time
240
Idle Time
48
Assembly Line Balancing Problem
CANDIDATE(S) FOR TASK 1 IN STATION 2
X
B
60
X
A
60
X
C
120
H
120
D
60
I
60
E
180
F
60
G
60
Assembly Line Balancing Problem
Balancing under the LOT assignment heuristic
Cycle time
288
seconds
288
seconds
288
seconds
864
seconds
Station
1
Station
2
Station
3
Total
A (60)
E (180)
C (120)
B (60)
Production Time
240
Idle Time
48
Assembly Line Balancing Problem
CANDIDATE(S) FOR TASK 2 IN STATION 2
X
B
60
X
A
60
X
C
120
H
120
D
60
X
E
180
F
60
I
60
G
60
Assembly Line Balancing Problem
Balancing under the LOT assignment heuristic
Cycle time
288
seconds
288
seconds
288
seconds
864
seconds
Station
1
Station
2
Station
3
Total
A (60)
E (180)
C (120)
D (60)
B (60)
Production Time
240
240
Idle Time
48
48
Assembly Line Balancing Problem
CANDIDATE(S) FOR TASK 1 IN STATION 3
X
B
60
X
A
60
X
C
120
H
120
X
X
D
60
E
180
F
60
I
60
G
60
Assembly Line Balancing Problem
Balancing under the LOT assignment heuristic
Cycle time
288
seconds
288
seconds
288
seconds
864
seconds
Station
1
Station
2
Station
3
Total
A (60)
E (180)
H (120)
C (120)
D (60)
B (60)
Production Time
240
240
Idle Time
48
48
Assembly Line Balancing Problem
CANDIDATE(S) FOR TASK 2 IN STATION 3
X
B
60
X
A
60
X
C
120
X
H
120
X
X
D
60
E
180
F
60
I
60
G
60
Assembly Line Balancing Problem
Balancing under the LOT assignment heuristic
Cycle time
288
seconds
288
seconds
288
seconds
864
seconds
Station
1
Station
2
Station
3
Total
A (60)
E (180)
H (120)
C (120)
D (60)
F (60)
B (60)
Production Time
240
240
Idle Time
48
48
Assembly Line Balancing Problem
CANDIDATE(S) FOR TASK 3 IN STATION 3
X
B
60
X
A
60
X
C
120
X
H
120
X
X
X
D
60
E
180
F
60
I
60
G
60
Assembly Line Balancing Problem
Balancing under the LOT assignment heuristic
Cycle time
288
seconds
288
seconds
288
seconds
864
seconds
Station
1
Station
2
Station
3
Total
A (60)
E (180)
H (120)
C (120)
D (60)
F (60)
B (60)
G (60)
Production Time
240
240
240
Idle Time
48
48
48
Assembly Line Balancing Problem
CANDIDATE(S) FOR TASK 1 IN STATION 4
X
B
60
X
A
60
X
C
120
X
H
120
X
X
X
D
60
E
180
F
60
X
G
60
I
60
Assembly Line Balancing Problem
Balancing under the LOT assignment heuristic
Cycle time
288
seconds
288
seconds
288
seconds
Station
1
Station
2
Station
3
Station
4
A (60)
E (180)
H (120)
I (60)
C (120)
D (60)
F (60)
B (60)
288
1,152
seconds seconds
Total
G (60)
Production
Time
240
240
240
60
780
Idle Time
48
48
48
228
372
Assembly Line Balancing Problem
Balancing under the LOT assignment heuristic
Cycle
time
288
seconds
288
seconds
288
seconds
Station
1
Station
2
Station
3
Station
4
A (60)
E (180)
H (120)
I (60)
C (120)
F (60)
D (60)
B (60)
G (60)
288
1,152
seconds seconds
Total
2nd
SOLUTION
Production
Time
240
240
240
60
780
Idle Time
48
48
48
228
372
Assembly Line Balancing Problem
Line
=
Efficiency
240 sec + 240 sec + 240 sec + 60 sec
288 sec x 4 stations
780 seconds
=
1,152 seconds
=
67.71%
Multiple Choice
28. In problem one, the efficiency of the assembly
line is:
a.
b.
c.
d.
64%
68%
70%
72%
Assembly Line Balancing Problem
Balance
Delay
Factor
48 sec + 48 sec + 48 sec + 228 sec
=
288 sec x 4 stations
372 seconds
=
1,152 seconds
=
32.29%
Multiple Choice
29. In problem one, the balance delay factor is:
a.
b.
c.
d.
28%
30%
32%
36%
Multiple Choice
30. In problem one, the tasks assigned to work
station ‘one’ are:
a.
b.
c.
d.
A,C
A,C,E
A,C,D
none of the above.
Assembly Line Balancing Problem
Balancing under the LOT assignment heuristic
Cycle time
288
seconds
288
seconds
288
seconds
864
seconds
Station
1
Station
2
Station
3
Total
A (60)
C (120)
B (60)
Production Time
240
Idle Time
48
Multiple Choice
31. In problem one, the tasks assigned to work
station ‘two’ are:
a.
b.
c.
d.
E,D
E,F
E,D or E,F
F,B,H,D
Assembly Line Balancing Problem
Balancing under the LOT assignment heuristic
Cycle time
288
seconds
288
seconds
288
seconds
864
seconds
Station
1
Station
2
Station
3
Total
A (60)
E (180)
C (120)
D (60)
B (60)
Production Time
240
240
Idle Time
48
48
Assembly Line Balancing Problem
Balancing under the LOT assignment heuristic
Cycle
time
288
seconds
288
seconds
288
seconds
Station
1
Station
2
Station
3
Station
4
A (60)
E (180)
H (120)
I (60)
C (120)
F (60)
D (60)
B (60)
G (60)
288
1,152
seconds seconds
Total
2nd
SOLUTION
Production
Time
240
240
240
60
780
Idle Time
48
48
48
228
372
Transportation Problem
Problem 2
TO
FROM
PLANT A
PLANT B
WAREHOUSE
1
WAREHOUSE
2
$19
30
WAREHOUSE
3
$22
WAREHOUSE
4
$25
PLANT
AVAILABILITY
$17
50
20
$24
$21
$19
$21
30
30
PLANT C
$29
$16
10
WAREHOUSE
DEMAND
$21
20
$26
70
40
150
30
60
20
40
150
Transportation Problem
REQUIREMENT:
Evaluate the empty cells via the stepping-stone technique.
a. A-3
b. B-1
c. B-3
1.
2.
3.
Do not attempt to evaluate any other empty cells
Do not attempt a transfer operation
Show all supporting calculations via “T” accounts
Problem 2
Transportation Problem
EVALUATE EMPTY CELL A-3
TO
FROM
PLANT A
PLANT B
WAREHOUSE
1
WAREHOUSE
2
-
$19
30
WAREHOUSE
3
$22
+
20
$24
$21
WAREHOUSE
4
$25
PLANT
AVAILABILITY
$17
50
$19
$21
30
30
PLANT C
$29
$16
10
WAREHOUSE
DEMAND
+
$21
20
-
$26
70
40
150
30
60
20
40
150
Transportation Problem
EVALUATE EMPTY ROUTE A-3
GROSS
INCREASE
A3
+ $25
C3
- $21
C2
+ $16
A2
- $22
+ $41
- $43
-$2
NET
DECREASE
GROSS
DECREASE
Multiple Choice
32. In problem two, the evaluation number for
empty cell ‘A-3’ is:
a.
b.
c.
d.
e.
- 4
+4
-10
+10
none of the above.
Transportation Problem
EVALUATE EMPTY CELL B-1
TO
FROM
PLANT A
PLANT B
PLANT C
WAREHOUSE
1
30
-
WAREHOUSE
2
$19
$22
$24
$25
PLANT
AVAILABILITY
$17
50
$21
$19
$21
30
-
30
$29
$16
10
WAREHOUSE
DEMAND
WAREHOUSE
4
+
20
+
WAREHOUSE
3
$21
20
$26
70
40
150
30
60
20
40
150
Transportation Problem
EVALUATE EMPTY ROUTE B-1
GROSS
INCREASE
B1
+ $24
A1
- $19
A2
+ $22
B2
- $21
+ $46
- $40
+$6
NET
INCREASE
GROSS
DECREASE
Multiple Choice
33. In problem two, the evaluation number for
empty cell ‘B-1’ is:
a.
b.
c.
d.
e.
- 9
+9
- 7
+7
none of the above.
Transportation Problem
EVALUATE EMPTY CELL B-3
TO
FROM
PLANT A
PLANT B
WAREHOUSE
1
WAREHOUSE
2
$19
30
$22
$24
$25
PLANT
AVAILABILITY
$17
50
- $21
$19
$16
$21
$29
10
WAREHOUSE
DEMAND
WAREHOUSE
4
20
30
PLANT C
WAREHOUSE
3
+
$21
30
+
-
20
$26
70
40
150
30
60
20
40
150
Transportation Problem
EVALUATE EMPTY ROUTE B-3
GROSS
INCREASE
B3
+ $19
C3
- $21
C2
+ $16
B2
- $21
+ $35
- $42
-$7
NET
DECREASE
GROSS
DECREASE
Multiple Choice
34. In problem two, the evaluation number for
empty cell ‘B-3’ is:
a.
b.
c.
d.
e.
- 4
+4
- 3
+3
none of the above.
Transfer Operation Problem
Given the following transportation algorithm intermediate solution:
Problem 3
TO
FROM
PLANT A
PLANT B
WAREHOUSE
1
WAREHOUSE
2
$19
30
WAREHOUSE
3
$22
WAREHOUSE
4
$25
PLANT
AVAILABILITY
$17
50
20
$24
$21
$19
$21
30
30
PLANT C
$29
$16
10
WAREHOUSE
DEMAND
$21
20
$26
70
40
150
30
60
20
40
150
Transfer Operation Problem
REQUIREMENT:
Problem 3
1. Perform a transfer operation on empty cell A-4.
2. What are the new allocations for A-4’s evaluation
path?
DO NOT COMPUTE THE NEXT INTERMEDIATE SOLUTION OR ITS COSTS
Transfer Operation Problem
CELL A - 4 TRANSFER OPERATION
FROM
PLANT A
PLANT B
WAREHOUSE
1
WAREHOUSE
2
$19
30
WAREHOUSE
3
$22
20
WAREHOUSE
4
$25
PLANT
AVAILABILITY
$17
+
50
-
TO
$24
$21
$19
$21
30
30
PLANT C
$29
$16
10
WAREHOUSE
DEMAND
+
$21
20
$26
40
70
-
150
30
60
20
40
150
Multiple Choice
35. In problem three, the evaluation number for
empty cell ‘A-4’ is:
a.
b.
c.
d.
e.
+ 2
- 32
+ 15
- 15
none of the above.
Transfer Operation Problem
CELL A - 4 TRANSFER OPERATION
FROM
PLANT A
PLANT B
WAREHOUSE
1
WAREHOUSE
2
$19
WAREHOUSE
3
$22
30
$24
WAREHOUSE
4
$25
PLANT
AVAILABILITY
$17
+
50
20
-
TO
$21
$19
$21
30
30
PLANT C
$29
$16
30
WAREHOUSE
DEMAND
+
$21
20
$26
20
70
-
150
30
60
20
40
150
Transfer Operation Problem
NEW ALLOCATIONS FOR CELL A-4 EVALUATION PATH
TO
FROM
PLANT A
PLANT B
WAREHOUSE
1
WAREHOUSE
2
$19
WAREHOUSE
3
$22
WAREHOUSE
4
$25
30
PLANT
AVAILABILITY
$17
50
20
$24
$21
$19
$21
30
30
PLANT C
$29
$16
30
WAREHOUSE
DEMAND
$21
20
$26
70
20
150
30
60
20
40
150
Multiple Choice
36. In problem three, the new allocation for cell
‘A-4’ is:
a. 15
b. 20
c. 25
d. 30
e. none of the above.
Multiple Choice
37. In problem three, the new allocation for cell
‘C-2’ is:
a.
b.
c.
d.
e.
15
20
25
30
none of the above.
Multiple Choice
38. In problem three, the new allocation for cell
‘A-2’ is:
a. 15
b. 20
c. 25
d. 30
e. none of the above.
Gravity Location Problem
A garden center has three ( 3 ) retail locations in Massachusetts.
The firm wants to construct a new central distribution center for
servicing its three retail sites:
Problem 4
Retail
Location
Acton
Haverhill
Northampton
(X,Y)
Daily Truck
Round Trips
( 19,10 )
( 24,14 )
( 7,6 )
6
8
10
Map Coordinates
Gravity Location Problem
Problem 4
REQUIREMENT:
A. Compute the location of the proposed facility
in terms of the ‘x’ and ‘y’ coordinates.
NOTE: 1. Do not attempt to draw a graph.
2. The supporting calculations are sufficient.
Gravity Location Problem
( 19 x 6 ) + ( 24 x 8 ) + ( 7 x 10 )
X =
6 + 8 + 10
114 + 192 + 70
24
376
= 15.67
24
+
0 5 10 15 20 25
X
Multiple Choice
39. In problem four, the ‘X’ coordinate for the new
central distribution center is:
a. 9.67
b. 14.00
c. 15.67
d. 30
e. none of the above.
Gravity Location Problem
( 10 x 6 ) + ( 14 x 8 ) + ( 6 x 10 )
Y =
6 + 8 + 10
60 + 112 + 60
24
Y
15
10
232
+
= 9.67
24
5
0
X
0 5 10 15 20 25
Multiple Choice
40. In problem four, the ‘Y’ coordinate for the new
central distribution center is:
a. 9.67
b. 14.00
c. 15.67
d. 30
e. none of the above.
Gravity Location Problem
Y
+
HAVERHILL
15
ACTON
THE NEW
DISTRIBUTION
CENTER
( 15.67, 9.67 )
+
10
NORTHAMPTON
5
X
0
0
5
10
15
20
25
30
35
True or False
41. The sources of a transportation matrix are either factories or outside vendors.
TRUE
FALSE
42. Evaluation numbers are either ‘positive’ or ‘negative’.
TRUE
FALSE
43. When total source units exceed total destination units, an additional row must
be included on the transportation matrix.
TRUE
FALSE
True or False
44. Qualitative factors are considered in the use of the transportation algorithm by
the operations staff when locating retail facilities.
TRUE
FALSE
45. The gravity location model uses shipping costs to locate a central distribution
center.
TRUE
FALSE
46. The gravity location model locates the central distribution center at the geographic center of the distribution system.
TRUE
FALSE
True or False
47. The transshipment model can accommodate multiple levels of the supply chain
simultaneously.
TRUE
FALSE
48. The transshipment model can accommodate multiple modes of transport.
TRUE
FALSE
49. The transshipment model utilizes a sophisticated version of the transportation
algorithm.
TRUE
FALSE
50. The gravity location model draws part of its input from the current monthly or
quarterly forecasted demands at each facility in the distribution system.
TRUE
FALSE