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1.133 M.Eng. Concepts of Engineering Practice
Fall 2007
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PROJECT MANAGEMENT 1
Dr. Chu E. Ho
ARUP
October 1 2007
Some Observations from
Chase an Engineer Reports
What a Project Manager is most concerned with:-
Financial Issues
a. Engineering Design
b. Construction Scheduling
c. Control of Revenue Flow
“Engineers don’t make good financial
decisions”
“Scheduling is very important”
“The faster you finish, the more you save on fixed
costs and interests”
Fixed Costs
- Salary
- Overheads : Property
Office Rental
Equipment
Utilities
Variable Costs
- Bank Loans
- Professional Liability Insurance
- Performance Bond
- Payment Bond
Activities – Logical Sequence
1. Instrumentation
2. Slurry wall installation
3. Jet grouting
4. Foundation installation
5. King posts and decking erection
6a. Excavation
6b. Strut installation + preloading
6a. Excavation
6b. Strut installation + preloading
7a. Cutting off pileheads
7b. Casting Pilecaps
7c. Casting base slab
8. Casting columns + intermediate floor slabs
8. Casting columns + intermediate floor slabs
9. Casting ground floor slab
NETWORK SCHEDULING
SCHEDULING
Activity Network
A graphical representation describing connections between all
all
activities in a project
Activity Path
A continuous string of activities within the network from
beginning to end
Critical Path
The activity path with the longest duration, in which any delay
of one activity causes a similar delay to the entire project
completion
ACTIVITY RELATIONSHIPS
Finish-Start
FS = Δ
Activity j may start Δ units of
time after finishing activity i
Normal
FS = 0
Activity j may start immediately
after finishing activity i
Start-Start
SS = Δ
Activity j may start Δ units of
time after starting activity i
Finish-Finish FF = Δ
Activity j may finish Δ units of
time after finishing activity i
TIME TO START/FINISH
Activity Duration di
Earliest Start
ESi
Earliest Finish EFi
The esti
mated duration
estimated
duration of each activity
The earliest time that activity i may start
The earliest time that activity i may finish
EFi = ESi + di
Latest Start
LSi
The latest time that activity i may start
Latest Finish
LFi
The latest time that activity i may finish
LSi = LFi - di
FLOAT TIME
Total Float tfii
The total time that activity i may be
postponed without delaying project
completion
tfi = LSi - ESi or LFi - EFi
Free Float
ffi
The maximum time that activity i may
be postponed without delaying the
earliest start (ESj) or earliest finish (EFj)
of any following activity j
ACTIVITY SYMBOLS
Activity i
ESi
Activity j
EFi
di
LSi
tf i
CODEi
ESj
EFj
dj
Δ
LFi
LSj
ff i
tf j
Type of Relationship
( FS, SS or FF)
LFj
CODEj
ff j
8 STEPS FOR NETWORK
ANALYSIS
1. List all the activities
2. Assign duration for each activity
3. Set up Network Diagram
4. Carry out Forward Calculations for ES
and EF
5. Determine Project Completion Time
6. Carry out Backward Calculations for LS
and LF
7. Determine Float available tf and ff
8. Identify Critical Path(s)
Schedule computation
Earliest Start (ESj) and Earliest Finish (EFj)
of the subsequent activity j
1. Calculate all possible ES times for activity j:
FS relationship,
SS relationship,
FF relationship,
ESj = EFi + Δ
ESj = ESi + Δ
ESj = {EFi + Δ} - dj
2. Select the latest time for ESj
3. Calculate
EFj = ESj + dj
Latest Start (LSi) and Latest Finish (LFi)
of the previous activity i
1. Calculate all possible LF times for activity i:
FS relationship,
SS relationship,
FF relationship,
LFi = LSj - Δ
LFi = {LSj - Δ} + di
LFi = LFj - Δ
2. Select the earliest time for LFi
3. Calculate
LSi = LFi - di
CALCULATIONS FOR
FLOAT
TOTAL FLOAT
1. Need to know ES, EF, LS and LF for
activity i
2. Calculate tf for activity i
tfi = {LSi– ESi } or {LFi - EFi}
FREE FLOAT
1. Calculate all possible ff between
activity i and j:
FS relationship, ffi = {ESj - EFi} - Δ
SS relationship, ffi = {ESj - ESi} - Δ
FF relationship, ffi = {EFj - EFi} - Δ
2. Select the smallest time gap for ffi
Network
Scheduling
Example Analysis
Set up Network Diagram
FS = 2
FS = 0
5
1
H
K
FS = 0
3
8
B
D
FS = 0
0
0
0
FS = 0
FS = 0
2
4
FF = 3
FF = 4
FS = 0
FS = (-2)
A
FS = 0
5
FS = 0
G
OPEN
8
FS = (-3)
C
FS = 0
FS = 0
E
12
FF = 2
SS = 2
J
5
FS = 0
F
FF = 1
2
I
P1
Carry out Forward Computation for Earliest Start and Earliest Finish
FS = 2
FS = 0
5
1
H
K
FS = 0
2
3
5
5
8
FS = 0
FS = 0
B
0
0
0
2
D
FS = 0
2
4
FF = 3
FF = 4
FS = 0
FS = (-2)
A
FS = 0
5
FS = 0
G
OPEN
8
FS = (-3)
C
FS = 0
FS = 0
E
12
FF = 2
SS = 2
J
5
FS = 0
F
FF = 1
2
I
P2
Carry out Forward Computation for Earliest Start and Earliest Finish
FS = 2
FS = 0
5
1
H
K
FS = 0
2
3
5
5
8
FS = 0
FS = 0
B
0
0
0
2
D
FS = 0
2
4
FF = 3
FF = 4
FS = 0
FS = (-2)
A
FS = 0
3
5
8 FS = 0
G
OPEN
8
FS = (-3)
C
FS = 0
FS = 0
E
12
FF = 2
SS = 2
J
5
FS = 0
F
FF = 1
2
I
P3
Carry out Forward Computation for Earliest Start and Earliest Finish
FS = 2
FS = 0
5
1
H
K
FS = 0
2
3
5
5
8
13
FS = 0
FS = 0
B
0
0
0
2
D
FS = 0
2
4
FF = 3
FF = 4
A
FS = 0
3
5
8 FS = 0
C
8
8
FS = 0
FS = (-2)
16
FS = (-3)
E
FS = 0
G
OPEN
FS = 0
12
FF = 2
SS = 2
J
5
FS = 0
F
FF = 1
2
I
P4
Carry out Forward Computation for Earliest Start and Earliest Finish
FS = 2
FS = 0
16
5
21
23
1
24
FS = 0
2
3
5
5
8
13
H
K
FS = 0
FS = 0
B
0
0
0
2
D
FS = 0
2
4
FF = 3
FF = 4
A
FS = 0
3
5
8 FS = 0
C
8
8
FS = 0
FS = (-2)
16
FS = (-3)
E
FS = 0
G
OPEN
FS = 0
12
FF = 2
SS = 2
J
5
FS = 0
F
FF = 1
2
I
P5
Carry out Forward Computation for Earliest Start and Earliest Finish
FS = 2
FS = 0
16
5
21
23
1
24
FS = 0
2
3
5
5
8
13
H
K
FS = 0
FS = 0
B
0
0
0
2
D
FS = 0
2
14
FF = 3
FF = 4
A
FS = 0
3
5
8 FS = 0
C
8
8
FS = 0
FS = (-2)
16
FS = (-3)
E
4
18
FS = 0
G
OPEN
FS = 0
13
12
25
FF = 2
SS = 2
J
5
FS = 0
F
FF = 1
2
I
P6
Carry out Forward Computation for Earliest Start and Earliest Finish
FS = 2
FS = 0
16
5
21
23
1
24
FS = 0
2
3
5
5
8
13
H
K
FS = 0
FS = 0
B
0
0
0
2
D
FS = 0
2
14
FF = 3
FF = 4
A
FS = 0
3
5
8 FS = 0
C
8
8
FS = 0
FS = (-2)
16
FS = (-3)
E
4
18
FS = 0
G
OPEN
FS = 0
13
12
25
FF = 2
SS = 2
J
13
5
18
FS = 0
F
FF = 1
2
I
P7
Carry out Forward Computation for Earliest Start and Earliest Finish
FS = 2
FS = 0
16
5
21
23
1
24
FS = 0
2
3
5
5
8
13
H
K
FS = 0
FS = 0
B
0
0
0
2
D
FS = 0
2
14
FF = 3
FF = 4
A
FS = 0
3
5
8 FS = 0
C
8
8
FS = 0
FS = (-2)
16
FS = (-3)
E
4
18
FS = 0
G
OPEN
FS = 0
13
12
25
FF = 2
SS = 2
J
13
5
18
FS = 0
F
FF = 1
17
2
I
P8
19
Carry out Forward Computation for Earliest Start and Earliest Finish
FS = 2
FS = 0
16
5
21
23
1
24
FS = 0
2
3
5
5
8
13
H
K
FS = 0
FS = 0
B
0
0
0
2
D
FS = 0
2
14
FF = 3
FF = 4
A
FS = 0
3
5
8 FS = 0
C
8
8
FS = 0
FS = (-2)
16
FS = (-3)
E
4
18
FS = 0
G
12
25
FF = 2
SS = 2
J
13
5
18
FS = 0
F
FF = 1
17
2
I
P9
19
25
OPEN
FS = 0
13
25
Carry out Backward Computation for Latest Start and Latest Finish
FS = 2
FS = 0
16
5
21
23
1
FS = 0
2
3
5
5
8
13
H
K
FS = 0
FS = 0
B
0
0
0
2
D
FS = 0
2
14
FF = 3
FF = 4
A
FS = 0
3
5
8 FS = 0
C
8
8
FS = 0
FS = (-2)
16
FS = (-3)
E
4
18
25
FS = 0
G
12
FF = 2
25
25
J
13
5
18
FS = 0
F
FF = 1
17
2
I
19
25
25
25
25
25
OPEN
FS = 0
13
SS = 2
P10
24
25
Carry out Backward Computation for Latest Start and Latest Finish
FS = 2
FS = 0
16
5
21
23
24
FS = 0
2
3
5
5
8
13
H
FS = 0
B
2
D
FS = 0
2
FF = 3
FF = 4
A
FS = 0
3
5
8 FS = 0
C
8
8
FS = 0
FS = (-2)
16
FS = (-3)
E
14
21
SS = 2
4
18
25
FS = 0
G
12
25
25
J
13
5
18
FS = 0
F
FF = 1
17
23
2
I
19
25
25
25
25
25
OPEN
FS = 0
13
13
FF = 2
P11
24
25
K
FS = 0
0
0
0
1
Carry out Backward Computation for Latest Start and Latest Finish
FS = 2
FS = 0
16
17
FS = 0
2
3
5
5
8
13
5
21
22
23
24
H
FS = 0
B
2
D
FS = 0
2
FF = 3
FF = 4
A
FS = 0
3
5
8 FS = 0
C
8
8
FS = 0
FS = (-2)
16
FS = (-3)
E
14
21
FF = 2
4
18
25
FS = 0
G
12
25
25
J
13
19
5
18
24
FS = 0
F
FF = 1
17
23
2
I
19
25
25
25
25
25
OPEN
FS = 0
13
13
SS = 2
P12
24
25
K
FS = 0
0
0
0
1
Carry out Backward Computation for Latest Start and Latest Finish
FS = 2
FS = 0
16
17
FS = 0
2
3
5
5
9
FS = 0
B
0
0
0
2
8
13
17
D
FF = 4
A
FS = 0
3
5
8 FS = 0
C
8
8
8
23
24
24
25
K
FS = 0
FS = 0
FS = (-2)
16
16 FS = (-3)
E
14
21
4
18
25
FS = 0
G
12
25
25
J
5
18
24
FS = 0
F
FF = 1
17
23
2
I
19
25
25
25
25
25
OPEN
FS = 0
13
13
FF = 2
13
19
1
FS = 0
SS = 2
P13
21
22
H
2
FF = 3
5
Carry out Backward Computation for Latest Start and Latest Finish
FS = 2
FS = 0
16
17
FS = 0
2
3
5
5
9
FS = 0
B
0
0
0
2
8
13
17
D
FF = 4
A
FS = 0
3
3
5
8 FS = 0
8
C
8
8
8
23
24
24
25
K
FS = 0
FS = 0
FS = (-2)
16
16 FS = (-3)
E
14
21
4
18
25
FS = 0
G
12
25
25
J
5
18
24
FS = 0
F
FF = 1
17
23
2
I
19
25
25
25
25
25
OPEN
FS = 0
13
13
FF = 2
13
19
1
FS = 0
SS = 2
P14
21
22
H
2
FF = 3
5
Carry out Backward Computation for Latest Start and Latest Finish
FS = 2
FS = 0
16
17
FS = 0
2
2
FS = 0
3
5
5
5
9
B
0
0
0
2
8
13
17
D
FF = 4
A
FS = 0
3
3
5
8 FS = 0
8
C
8
8
8
23
24
24
25
K
FS = 0
FS = 0
FS = (-2)
16
16 FS = (-3)
E
14
21
4
18
25
FS = 0
G
12
25
25
J
5
18
24
FS = 0
F
FF = 1
12
23
2
I
19
25
25
25
25
25
OPEN
FS = 0
13
13
FF = 2
13
19
1
FS = 0
SS = 2
P15
21
22
H
2
FF = 3
5
Carry out Backward Computation for Latest Start and Latest Finish
FS = 2
FS = 0
16
17
FS = 0
2
2
FS = 0
3
5
5
5
9
B
0
0
0
2
2
2
8
D
FF = 3
FF = 4
A
FS = 0
3
3
13
17
5
8 FS = 0
8
C
8
8
8
21
22
23
24
H
24
25
K
FS = 0
FS = 0
FS = (-2)
16
16 FS = (-3)
E
14
21
4
18
25
FS = 0
G
12
25
25
J
5
18
24
FS = 0
F
FF = 1
12
23
2
I
19
25
25
25
25
25
OPEN
FS = 0
13
13
FF = 2
13
19
1
FS = 0
SS = 2
P16
5
Calculating Total Float
FS = 2
FS = 0
16
17
1
FS = 0
2
2
0
FS = 0
0
0
0
2
3
5
5
5
9
4
B
2
2
FF = 3
8
D
FF = 4
A
FS = 0
3
3
0
5
8 FS = 0
8
C
8
8
0
13
17
8
23
24
1
H
1
24
25
K
FS = 0
FS = 0
FS = (-2)
16
16 FS = (-3)
FF = 2
5
18
24
FF = 1
2
I
4
18
25
FS = 0
G
FS = 0
12
25
25
J
FS = 0
F
17
23
6
14
21
7
13
13
0
SS = 2
P17
21
22
FS = 0
E
13
19
6
5
19
25
25
25
0
25
25
OPEN
Calculating Free Float
FS = 2
FS = 0
16
17
1
FS = 0
2
2
0
FS = 0
0
0
0
2
A
3
B
2
2
0
5
5
0
FF = 3
FS = 0
3
3
0
5
C
5
9
4
8
D
FF = 4
8 FS = 0
8
0
8
8
0
8
E
13
17
1
F
18
24
0
P18
2
I
14
21
7
4
G
18
25
7
FS = 0
FS = 0
13
13
0
12
J
25
25
0
FS = 0
FF = 1
17
23
6
23
24
1
1
K
24
25
1
FS = 0
FS = 0
FS = (-2)
16
16 FS = (-3)
0
FF = 2
5
H
21
22
0
FS = 0
SS = 2
13
19
6
5
19
25
6
25
25
0
25
25
OPEN 0
Identify Critical Path
FS = 2
FS = 0
16
17
1
FS = 0
2
2
0
FS = 0
0
0
0
2
A
3
B
2
2
0
5
5
0
FF = 3
FS = 0
3
3
0
5
C
5
9
4
8
D
FF = 4
8 FS = 0
8
0
8
8
0
8
E
13
17
1
F
14
21
7
4
G
13
13
0
12
J
18
24
0
P19
2
I
18
25
7
FS = 0
FS = 0
25
25
0
FS = 0
FF = 1
17
23
6
23
24
1
1
K
24
25
1
FS = 0
FS = 0
FS = (-2)
16
16 FS = (-3)
0
FF = 2
5
H
21
22
0
FS = 0
SS = 2
13
19
6
5
19
25
6
Critical Path A-B-C-E-J
25
25
0
25
25
OPEN 0