Showing how the Sequence Step Algorithm, a simulation-based scheduling algorithm models and solves scheduling problem of repetitive project with probabilistic activity durations.

1. (III) Example of SQS-AL 1
EXAMPLE OF SCHEDULING
A REPETITIVE PROJECT WITH
PROBABILISTIC ACTIVITY DURATIONS
Eliminating Idle Time in Resource Utilization
Using the Sequence Step Algorithm, SQS-AL
Presented by
Chachrist Srisuwanrat
2008

2. (III) Example of SQS-AL 2
EXAMPLE 2
Work Amount (Work Units)
Uni
t
A B C D E F G
1 100 150 200 150 100 150 50
2 250 100 150 200 150 250 200
3 150 200 50 100 50 50 50
4 200 150 200 150 100 100 150
Productivity
(Work Units/Time Units)
Activity Mean SD
A 10 1.0
B 20 2.0
C 15 1.5
D 15 1.5
E 25 2.5
F 15 1.5
G 20 2.0
A
B
C
D
E
F
G
SQS1 SQS2 SQS3 SQS4
For example, A1 duration on average is 100/10 = 10 time units

3. (III) Example of SQS-AL 3
Results from sequence step 2
replication 1 (SQS2_n1)
RSM_SQS1_n1
0
1
2
3
4
0 10 20 30 40 50 60 70 80 90 100 110 120 130
Time
Unit
A B C D E F G
Crew Idle Time of B (CITB)

4. (III) Example of SQS-AL 4
Collected Crew Idle Time (CIT) at
the end of SQS2
CITB
Range % Frequency
< 35 0.01
< 40 1.26
< 45 19.37
< 50 65.92
< 55 94.27
< 60 99.40
< 65 99.95
< 70 99.99
< 75 100.00
CITC
Range % Frequency
< 25 0.01
< 30 0.03
< 35 0.09
< 40 15.33
< 45 57.92
< 50 90.67
< 55 98.94
< 60 99.92
< 65 100.00

5. (III) Example of SQS-AL 5
Result from sequence step 3
replication 1 (SQS3_n1)
RSM_SQS2_n1
0
1
2
3
4
0 10 20 30 40 50 60 70 80 90 100 110 120 130
Time
Unit
A B C D E F G
B starts at date 55
C starts at date 50

6. (III) Example of SQS-AL 6
Collected Crew Idle Time (CIT) at the
end of SQS3
CITD
Range % Frequency
< 60 0.00
< 65 62.14
< 70 99.50
< 75 99.99
< 80 100.00
CITE
Range % Frequency
< 65 0.00
< 70 1.84
< 75 74.66
< 80 99.67
< 85 99.99
< 90 100.00
CITF
Range % Frequency
< 55 0.00
< 60 0.05
< 65 63.24
< 70 99.39
< 75 99.99
< 80 100.00
CITB
Range % Frequency
< 0 0.00
< 5 99.48
< 10 99.97
< 15 100.00
CITC
Range % Frequency
< 0 0.00
< 5 98.92
< 10 99.95
< 15 100.00

7. (III) Example of SQS-AL 7
Result from sequence step 4
replication 1 (SQS4_n1)
RSM_SQS3_n1
0
1
2
3
4
0 10 20 30 40 50 60 70 80 90 100 110 120 130
Time
Unit
A B C D E F G

8. (III) Example of SQS-AL 8
Collected Crew Idle Time (CIT)
at the end of SQS3
CITB
Range % Frequency
< 0 0.00
< 5 99.52
< 10 99.98
< 15 100.00
CITC
Range % Frequency
< 0 0.00
< 5 99.06
< 10 99.92
< 15 100.00
CITD
Range % Frequency
< 5 0.00
< 10 100.00
CITE
Range % Frequency
< 0 0.00
< 5 100.00
CITF
Range % Frequency
< 0 0.00
< 5 100.00
CITG
Range % Frequency
< 90 0.00
< 95 21.44
< 100 93.09
< 105 99.92
< 110 100.00

9. (III) Example of SQS-AL 9
Result from sequence step 5*
replication 1 (SQS5_n1)
RSM_SQS4_n1
0
1
2
3
4
0 10 20 30 40 50 60 70 80 90 100 110 120 130
Time
Unit
A B C D E F G

10. (III) Example of SQS-AL 10
Final Crew Idle Times
CITB
Range % Frequency
< 0 0.00
< 5 99.39
< 10 99.95
< 15 100.00
CITC
Range % Frequency
< 0 0.00
< 5 99.11
< 10 99.94
< 15 100.00
CITD
Range % Frequency
< 5 0.00
< 10 100.00
CITE
Range % Frequency
< 0 0.00
< 5 100.00
CITF
Range % Frequency
< 0 0.00
< 5 100.00
CITG
Range % Frequency
< 0 0.00
< 5 99.90
< 10 100.00

11. (III) Example of SQS-AL 11
Results from Each Sequence Step
Average CIT
SQS
A B C D E F G
2 0 48 44 54 66 54 79
3 0 0 0 64 73 64 90
4 0 0 0 0 0 0 96
5* 0 0 0 0 0 0 0
Average Sum of Lags
Between Units
(UIT)
Assigned Crew Lead Time
(CLT)
Average
Project
Duration
Average
Project
Idle Time
SQS B C D E F G B C D E F G
2 38 34 30 48 30 45 0 0 0 0 0 0 102 225
3 0 0 1 11 1 16 55 50 0 0 0 0 113 29
4 0 0 0 0 0 12 55 50 70 80 70 0 119 12
5* 0 0 0 0 0 0 55 50 70 80 70 100 123 0
Conclusion
At 80% confidence of continuity,
average project duration is 123
day with 0 idle time.

12. (III) Example of SQS-AL 12
Balancing Between
Idle Time and
Project Duration
Total Idle Time and Project Duration
0
50
100
150
200
250
100 120 140 160 180
Average Project Duration
AverageIdleTime
20%
40%
60%
80%
100%
Confident Level SQS
Average
Project
Duration
Average
Project Idle
Time
100%
2 102 225
3 128 29
4 142 14
5 158 0
80%
2 102 225
3 113 29
4 119 12
5 123 0
60%
2 102 225
3 113 30
4 114 18
5 118 2
40%
2 102 226
3 108 31
4 109 18
5 113 5
20%
2 102 225
3 108 37
4 109 25
5 113 8