Ask
Login
0
2.1kviews
Draw the Network
written 8.3 years ago by gravatar for teamques10 teamques10 ★ 68k modified 2.8 years ago by gravatar for sagarkolekar sagarkolekar ★ 11k

The interdependence of a job consisting of 7 activities & time estimates are given in following table.

Draw Network & Determine:-

1) Project duration corresponding to 50 % probability..

2) Probability of completing the project in 35 days.

Z -3 -2 -1 0 1 2 3
P(%) 0.13 2.28 15.87 50 84.13 97.72 99.87
Activity Preceding Activity Succeeding Activity $T_0$ $T_m$ $T_p$
A - C & E 6 9 12
B - D & E 5 8 17
C A G 4 7 22
D B G 4 7 16
E A - 4 7 10
F B - 2 5 8
G C & D - 4 10 22


construction management
ADD COMMENT EDIT
1 Answer
0
35views
written 8.3 years ago by gravatar for teamques10 teamques10 ★ 68k
Activity $T_0$ $T_m$ $T_p$ $t_e = \frac{t_0 + 4t_m + t_p}{6}$ $\sigma = \frac{t_p - t_0}{6}$ $\sigma^2$
A 6 9 12 9 1 1
B 5 8 17 9
C 4 7 22 9 3 9
D 4 7 16 8
E 4 7 10 7
F 2 5 8 5
G 4 10 22 11 3 9
$\sigma^2 = 19$

enter image description here

Project duration = 29 Days

Critical path = A-C-G =10-20-40-50

Step: 3

  1. Probability % = 50 %

    For probability 50 % the scheduled time will be same as that of the project duration.

    ∴ Duration= 29 Days

  2. Probability of completing the project in 35 Days

    z $= \frac{\text{Scheduled Time-Project Duration}}{∈}$

    S.T.= 35 Days

    P.D.= 29 Days . $∈=√\sqrt{σ^2} = \sqrt{19} = 4.36$

    z $= \frac{35-29}{4.36} = 1.376$

By interpolation,

enter image description here

$\boxed{P \% = 89.23 \%}$
ADD COMMENT EDIT
Please log in to add an answer.