Mumbai University > Civil Engineering > SEM 8 > Construction Management

Marks: 10M

Following is the data of associated with PERT project

i) Determine the variance of the project

ii) What is the probability of completing the project in 29 days?

iii) What is the schedule duration with 90% probability?

1. Project Duration: 29 Days

   Critical path: 10-20-40-50 i.e. A-C-G

2. Probability of completing project in 29 days:

   $T_s$: Scheduled completion time

   $T_E$: Estimated Time of completion

   $z =\frac{T_s- T_E}{\sigma} = \frac{T_s - T_E}{\sqrt{\sigma^2}}$

$\sqrt{\sigma^2} = \sqrt{\text{Sum of variance of critical path}}=\sqrt{19}=4.35$

Z = 0

P% for corresponding Z value = 50%

Therefore, Probability of completing project in 29 days is 50%.

1. What is the schedule duration with 90% probability?

For 90% probability:

$\frac{(0.977 - 0.841)}{(2 - 1)} = \frac{(0.977 - 0.90)}{(2 - x)}$

X= 1.43

Therefore,

$z=1.43= \frac{T_s - T_E}{\sigma}$

$1.43 = \frac{T_s- 29}{4.35}$

$T_s= 35.2205 \text{Days}$

Schedule duration with 90% probability is 35.220 Days.