Question

What will be the expected time for driving the precast piles for a bridge abutment activity having optimistic time 22, most likely time 30, and pessimistic time 50?

• A. 34 days
• B. 32 days
• C. 42 days
• D. 40 days

Hint:

For time estimation under uncertainty, use $T_e = \frac{T_o + 4T_m + T_p}{6}$. Weight the most likely time more heavily for better accuracy.

Answer 1

The Correct Option is B

The PERT method's expected time ($T_e$) formula is:
\[T_e = \frac{T_o + 4T_m + T_p}{6}\]
Here:
$T_o =$ Optimistic time,
$T_m =$ Most likely time,
  $T_p =$ Pessimistic time.
Given values:
\[T_o = 22, \quad T_m = 30, \quad T_p = 50\]
Substituting values:
\[T_e = \frac{22 + 4(30) + 50}{6}\]
Simplifying:
\[T_e = \frac{22 + 120 + 50}{6}\]
\[T_e = \frac{192}{6}\]
Calculation:
\[T_e = 32 \, \text{days}\]