Question

To complete the rotor assembly for an experimental spacecraft, Gilbert has laid out nine major activities involved. These activities have been labelled A to I in the table below, which also shows their estimated completion × (in weeks) and their immediate predecessors.

EVENTS AND ACTIVITIES FOR ROTOR ASSEMBLY
ACTIVITIES × (IN WEEKS) PRECEDING EVENT
A M B
A 1 2 3 -
B 2 3 4 A
C 4 5 6 A
D 8 9 10 A
E 2 5 8 B
F 4 5 6 B, C
G 1 2 3 F, D
H 1 3 5 E, F
I 2 4 6 H, G
Key: A is optimist time, M is the most likely time and B is the pessimistic time.
Calculate the expected time for each activity.
a) 2.0, 3.0, 5.0, 9.0, 5.0, 5.0, 2.0, 3.0, 4.0
b) 2.0, 4.0, 5.0, 9.0, 5.0, 5.0, 2.0, 3.0, 4.0
c) 2.0, 4.0, 5.0, 9.0, 5.0, 6.0, 2.0, 3.0, 4.0
d) 2.0, 4.0, 6.0, 9.0, 5.0, 5.0, 2.0, 3.0, 4.0

Answer 1

The expected time for each activity in the rotor assembly can be calculated using the formula: Expected Time = (Optimistic Time + 4 x Most Likely Time + Pessimistic Time) / 6.

Step-by-step explanation:

To calculate the expected time for each activity, we can use the formula:

Expected Time = (Optimistic Time + 4 x Most Likely Time + Pessimistic Time) / 6

Using this formula for each activity, we can calculate the expected times as follows:

A: (1 + 4 x 2 + 3) / 6 = 2.0

B: (2 + 4 x 3 + 4) / 6 = 3.0

C: (4 + 4 x 5 + 6) / 6 = 5.0

D: (8 + 4 x 9 + 10) / 6 = 9.0

E: (2 + 4 x 5 + 8) / 6 = 5.0

F: (4 + 4 x 5 + 6) / 6 = 5.0

G: (1 + 4 x 2 + 3) / 6 = 2.0

H: (1 + 4 x 3 + 5) / 6 = 3.0

I: (2 + 4 x 4 + 6) / 6 = 4.0