Question

In PERT analysis, the expected time to complete an activity is computed from the three-time estimates: a most likely time (m), an optimistic time (a), and a pessimistic time (b) using the expression

• A. \(\frac{a + 4m + b}{6}\)
• B. \(\frac{4a + 4 + b}{6}\)
• C. \(\frac{a + m + 4b}{6}\)
• D. \(\frac{a + m + b}{3}\)

Hint:

In PERT analysis, always remember the weighted average formula \(\frac{a + 4m + b}{6}\) — it emphasizes the most likely duration (m) for better project time estimation.

Answer 1

The Correct Option is A

In PERT (Program Evaluation and Review Technique), the expected time (\(T_e\)) to complete an activity is calculated using a weighted average of three time estimates:

• \(a\): Optimistic time (the minimum time required to complete the task),
• \(m\): Most likely time (the best estimate of the time required),
• \(b\): Pessimistic time (the maximum time required).

The formula is: \[ T_e = \frac{a + 4m + b}{6} \] This formula gives more weight to the most likely time estimate, reflecting the assumption that it is more probable than the optimistic or pessimistic values.