www.qvive.biz calculating float activityprecedenceduration start0 d 4 a 6 fd, a7 ed8 gf, e5 bf5 hg7...
TRANSCRIPT
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Calculating Float
Activity Precedence
Duration
Start 0
D Start 4
A Start 6
F D, A 7
E D 8
G F, E 5
B F 5
H G 7
C H 8
End C, B 0
1. What is the duration of the critical path?A) 32B) 33C) 31D) 35
2. What is the float of activity B?A) 0B) 16C) 10D) 15
3. What is the float of Activity F?A) 0B) 5C) 13D) 7
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NOTE: This examples uses the “day 0” method for the calculations. Starting the project on day 0 results in easier math.
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Start End“A” “B”
“C”“D” “E”
“F”
“G” “H”
“X”ES EF
LS LF
D
F
1. Precedence Diagram 2. Durations3. Forward Pass (ES EF)4. Critical Path5. Float of Critical Path Activities6. Backward Pass (LF LS)
Q A
1
2
3
1. Precedence Diagram
Calculating Float BEST VIEWED IN SLIDE SHOW MODE
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Start End“A” “B”
“C”“D” “E”
“F”
“G” “H”
“X”ES EF
LS LF
D
F
1. Precedence Diagram 2. Durations3. Forward Pass (ES EF)4. Critical Path5. Float of Critical Path Activities6. Backward Pass (LF LS)
Q A
1
2
3
Calculating Float
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“A” “B”
“C”“D” “E”
“F”
“G” “H”
Start End
Q A
1
2
3
6 5
84 8
7
5 7
“X”ES EF
LS LF
D
F
1. Precedence Diagram 2. Durations3. Forward Pass (ES EF)4. Critical Path5. Float of Critical Path Activities6. Backward Pass (LF LS)
Calculating Float
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“A”0
“B”
“C”“D”0
“E”
“F”
“G” “H”
Start End
“X”ES EF
LF
D
F
1. Precedence Diagram 2. Durations3. Forward Pass (ES EF)4. Critical Path5. Float of Critical Path Activities6. Backward Pass (LF LS)
Q A
1
2
3
6 5
84 8
7
5 7
6
4
6 13
4 12
13 18
25 3313 18 18 25
The latest Late Finish of the preceding activities determines Early Start
6
4
13
12
0 + 6 = 6
Calculating Float
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“A”0 66
“B”13 185
“C”25 338
“D”0 44
“E”4 128
“F”6 137
“G”13 185
“H”18 257
Start End
“X”ES EF
LS LF
D
F
1. Precedence Diagram 2. Durations3. Forward Pass (ES EF)4. Critical Path5. Float of Critical Path Activities6. Backward Pass (LF LS)
Q A
1
2
3
The latest Early Finish of the preceding activities determines Critical Path
12
13 18
33
6
4
Calculating Float
B
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“A”0 66
“B”13 185
“C”25 338
“D”0 44
“E”4 128
“F”6 137
“G”13 185
“H”18 257
Start End
“X”ES EF
LS LF
D
F
1. Precedence Diagram 2. Durations3. Forward Pass (ES EF)4. Critical Path5. Float of Critical Path Activities6. Backward Pass (LF LS)
Q A
1 B
2
3
0
0
0
0 0
Activities on the Critical Path have Zero Float
Calculating Float
A
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“A”0 66
“B”13 185
“C”25 338
“D”0 44
“E”4 128
“F”6 137
“G”13 185
“H”18 257
Start End
“X”ES EF
LS LF
D
F
1. Precedence Diagram 2. Durations3. Forward Pass (ES EF)4. Critical Path5. Float of Critical Path Activities6. Backward Pass (LF LS)
Q A
1 B
2
3 A
0
0
0
0 0
0 6
25 33
6 13
13 18 18 25
Activities on the Critical Path have LS=ES and LF=EF
Calculating Float
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“A”0 6
0 6
6
0
“B”13 185
“C”25 33
25 33
8
0
“D”0 44
“E”4 128
“F”6 13
6 13
7
0
“G”13 18
13 18
5
0
“H”18 25
18 25
7
0
Start End
Q A
1 B
2
3 A
3328
1 5 5 13
15
1 1
“X”ES EF
LS LF
D
F
1. Precedence Diagram 2. Durations3. Forward Pass (ES EF)4. Critical Path5. Float of Critical Path Activities6. Backward Pass (LF LS)
The earliest Late Start of the following activities determines Late Finish
33 – 5 = 28
28 – 13 = 15
6
5
Calculating Float
D
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“A”0 6
0 6
6
0
“B”13 18
28 33
5
15
“C”25 33
25 33
8
0
“D”0 4
1 5
4
1
“E”4 12
5 13
8
1
“F”6 13
6 13
7
0
“G”13 18
13 18
5
0
“H”18 25
18 25
7
0
Start End
“X”ES EF
LS LF
D
F
1. Precedence Diagram 2. Durations3. Forward Pass (ES EF)4. Critical Path5. Float of Critical Path Activities6. Backward Pass (LF LS)
Q A
1 B
2 D
3 A
Calculating Float
What else can we learn from this example?
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“A”0 6
0 6
6
0
“B”13 18
28 33
5
15
“C”25 33
25 33
8
0
“D”0 4
1 5
4
1
“E”4 12
5 13
8
1
“F”6 13
6 13
7
0
“G”13 18
13 18
5
0
“H”18 25
18 25
7
0
Start End
“X”ES EF
LS LF
D
F
1. Precedence Diagram 2. Durations3. Forward Pass (ES EF)4. Critical Path5. Float of Critical Path Activities6. Backward Pass (LF LS)
Q A
1 B
2 D
3 A
1 1
Project has increased RISK because of a Near-Critical Path
Calculating Float