1. Scheduling of
Repetitive Projects
Repetitive Projects Scheduling
Linear Projects
Repetitive uniform of work (multiple houses, …)
Geometrically linear (pipeline, highways,…)
Some non typical units may exist
Projects assumed to be comprised of n typical units
Complex to schedule and monitor
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2. Repetitive Projects Scheduling
Duration-driven Vs Resource-driven Schedule
Duration-driven schedule
Basic units: activities, durations, relationships
Resources are functions of activities durations
Resources are assumed to be available
Resource-driven schedule
More focus on resources
Meeting a deadline
Line of balance (LOB)
Summary diagrams
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Repetitive Projects Scheduling
Line of Balance (LOB)
Meet deadline date
Focus on resources
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3. Repetitive Projects Scheduling
Line of Balance (LOB)
One Activity & 3 Crews
Site
5 Crew 2
4 Crew 1
3 Crew 3
2 Crew 2
1 Crew 1
0 1 2 3
Time
How Many Crews Needed to Meet Deadline ?
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Repetitive Projects Scheduling
Line of Balance (LOB)
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4. Repetitive Projects Scheduling
Line of Balance (LOB)
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Repetitive Projects Scheduling
Line of Balance (LOB)
Sites
Diff. Durations Parallel Crews Stagg. Crews
9
8
7
6
5
4
3
2
1
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Time
8
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5. Repetitive Projects Scheduling
Line of Balance Calculations
Crew synchronization and work continuity equation
Computation of project delivery rate to meets a deadline
Calculating resource needs
Drawing the LOB schedule
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Repetitive Projects Scheduling
Line of Balance Calculations
Crew synchronization and work continuity equation
Computation of project delivery rate to meets a deadline
Calculating resource needs
Drawing the LOB schedule
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6. Repetitive Projects Scheduling
Line of Balance Calculations (work continuity)
R=C/D C=DxR
Unit
5
4 Crew 1
3 Crew 3
2 Crew 2 C Crews
1 R Crew 1
0 1 2 3
D Time
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Repetitive Projects Scheduling
Line of Balance Calculations (work continuity)
R = 1 / (D / C) C=DxR
Unit
Crew 3
3
2 Crew 2
1
1 R Crew 1 Time
R
0 1 2 3
D/C D/C D/C
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7. Repetitive Projects Scheduling
Line of Balance Calculations (Meeting a deadline)
Units
n
.
.
.
n-1
2
R Time
1
T1 = CPM Duration of Unit 1
TL = Project Deadline Duration
R = (n – 1) / (TL - T1)
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Repetitive Projects Scheduling
Line of Balance Calculations (Meeting a deadline)
TF = 3 D (2)
A (5) B (5) C (5)
Unit n
A D D C
n-1
B
(TL - T1 ) + TFD
Unit 1 TL - T1
A (5) B (5) C (5)
D (2) TF = 3
R = (n – 1) / (TL - T1) + TF
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8. Repetitive Projects Scheduling
Line of Balance Calculations (work continuity)
Draw the CPM for one unit and determine activities floats; TFi
Calculate CPM duration for one unit; T1
Calculate Ri = (n-1) / (TL - T1) + TFi
Calculating Number of crews needed Ci = Ri x Di
Calculate actual number of crews Cai = Round up Ci
Then calculate actual delivery rates Rai = Cai / Di
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Repetitive Projects Scheduling
Line of Balance Calculations (Example)
A 5 Kilometer pipeline project
The activities involved in one Kilometer is given below
Project deadline 30 days
Assume 2 days buffer time between activities
Activity Duration
Activity name Preceding activities
no. (days)
1 Locate and clear 1 -
2 Excavate 3 1
3 String pipe 1 1
4 Lay pipe 4 2,3
5 Pressure test 1 4
6 Backfill 2 5
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9. Repetitive Projects Scheduling
Line of Balance Calculations (Example)
0 1 3 6 8 12 14 15 17 19
-2 2 (3) -2 4 (4) -2 5 (1) -2 6 (2)
1 (1)
0 1 3 6 8 12 14 15 17 19
-2 -2
3 4
3 (1)
5 6
T1 = 19 days
TL= 30 days
N = 5 units
Ri = (n-1) / TL - T1 + TFi = 4 / (11 + TFi)
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Repetitive Projects Scheduling
Line of Balance Calculations (Example)
Duration Total Ri = Cai =
Activity Ci =Di x Ri Rai = Cai / Di
Di Float 4 / (11+TFi) Round up Ci
1 1 0 0.364 0.364 1 1
2 3 0 0.364 1.092 2 0.667
3 1 2 0.308 0.308 1 1
4 4 0 0.364 1.456 2 0.5
5 1 0 0.364 0.364 1 1
6 2 0 0.364 0.728 1 0.5
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10. Repetitive Projects Scheduling
Line of Balance Calculations (Example)
Activity 1:
D= 1 day; R = 1 unit/day; Horizontal projection = n-1 / R = 4/1= 4
No. of
units 4 5 7 8 9 12 16 20 22 23 29 31
5
1 3 2 4 5 6
1 Time
0 1 3 4 6 8 12 18 19 21 23
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