Network Analysis MCQ with answer and solution

Concept

Program Evaluation and Review Technique (PERT)

Formula

tₑ = (tₒ + 4tₘ + tₚ) / 6

Step-by-step solution

1. Understand the three given statements regarding PERT (event-oriented nature, Beta distribution assumption, and Expected Time formula). 2. Verify that PERT is indeed an event-oriented technique for non-repetitive projects, uses a Beta distribution, and calculates expected time as tₑ = (tₒ + 4tₘ + tₚ) / 6. 3. Since all three statements are correct, select Option (d).

Explanation

All three statements are correct. PERT is designed for unique, non-repetitive projects like research and development, focusing on project events rather than routine activities. It uses a Beta probability distribution to model time uncertainty, and calculates the expected completion time using the weighted average formula (tₒ + 4tₘ + tₚ) / 6

Shortcut

To remember the main features of PERT, use the rule "PERT = Event, Beta, 1-4-1/6": - Event-oriented: Designed for non-repetitive R\&D projects focusing on events/milestones - Beta Distribution: Assumes Beta distribution for individual activity durations - 1-4-1/6 Formula: Expected time tₑ = (tₒ + 4tₘ + tₚ) / 6, where the middle/most likely time (tₘ) gets 4 times the weight

Common mistake

A common mistake is confusing PERT with CPM and incorrectly assuming PERT is activity-oriented rather than event-oriented. Another frequent error is confusing the probability distributions, as students often mistake the Beta distribution used for individual activity time estimates with the Normal distribution used for total project completion time. Additionally, students sometimes misremember the expected time formula by using an incorrect denominator or weight for the most likely time.