Z | 1.0 | 1.1 | 1.2 | 1.3 |
(Pr(%) | 84.13 | 86.43 | 88.49 | 90.32 |
tE=t0+4tL+tp6
σ2=(tp−t06)2
Variance calculation is given in the table below:
Critical path:
1 - 2 - 5 = 10 + 7 = 17
1 - 2 - 4 - 5= 10+9 + 11 = 30
1 - 3 - 4 - 5 = 9 + 8 + 11 =28
1 - 3 - 5 = 9 + 5 = 14
Critical path = 1 - 2 - 4 -5
To calculate σ
TE=30days;Ts=36days
Z=Ts−TEσ
σ2 of critical path
σ2=4+9+9=22
σ=√22=4.69
Z=36−304.69=1.27 =1.3
From the table
Z=1.3⇒probability=90.32%