Question

Which of the following statements is not correct about PERT ?

1. Network is constructed based on the events.
2. It does not take uncertainties involved in the estimation of times.
3. Network deals with uncertainties and hence three time estimations are considered.
4. As there is no certainty of time, activity duration cannot be reduced.

Answer 1

Correct Answer - Option 2 : It does not take uncertainties involved in the estimation of times.

Explanation:

PERT stands for "Project Evaluation and Review Technique". This network model is used for project scheduling.

 

Difference between PERT and CPM (Critical Path Method)

PERT	CPM
1. Probabilistic approach	1. Deterministic approach
2. Three-time estimate	2. One-time estimate
3. Event oriented network model	3. Activity-oriented network model
4. The slack concept is used	4. Float concept is used
5. Project crashing is not possible	5. Project crashing is possible
6. Deals with probabilistic time estimates.	6. Deals with deterministic time estimates.

 

PERT does take uncertainties involved in the estimation of times, therefore three-time estimates have been taken for the calculation project duration. They are optimistic (t_o), pessimistic (t_p), and most likely (t_m).

\(T_e=\frac{t_o\;+\;4t_m\;+\;t_p}{6}\)

Therefore, the option 2 is the incorrect statement among the given options.