The document presents a method for scheduling repetitive projects with probabilistic activity durations, utilizing the Sequence Step Algorithm (SQS-AL) to optimize resource utilization and minimize idle time. Several examples showcase the application of the algorithm across multiple steps, detailing collected crew idle time and project efficiency metrics. Results indicate an average project duration of 123 days with zero idle time at an 80% confidence level.

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