Which one of the following statements is correct?
- ACPM is developed especially for scheduling of research and development work.
- BPERT is developed for the quality control laboratory work at construction site.
- CPERT is a method of statistically evaluating project duration over a time-sensitive domain.Correct
- DA project schedule is a rough time table of construction operation.
Solution
Concept
PERT is a probabilistic (statistical) method to estimate project duration. CPM is a deterministic method.
Formula
te = (to + 4tm + tp)/6
Step-by-step solution
1. Check A: R&D work uses PERT, not CPM. CPM was made for construction and plant maintenance work. So A is wrong. 2. Check B: PERT was made for the Polaris missile R&D project, not for quality control lab work. So B is wrong. 3. Check C: PERT uses three time estimates and statistics (mean, variance) to find project duration and its probability. So C is correct. 4. Check D: A project schedule is a detailed time table, not a rough one. So D is wrong.
Explanation
PERT is a statistical method. It uses optimistic, most likely and pessimistic times to find the expected project duration and the chance of finishing on time. So statement C is correct.
Why the other options are wrong
A: R&D scheduling is done by PERT, not CPM. B: PERT was not made for quality control lab work. D: A schedule is a detailed time table, not a rough one.
Shortcut
PERT = Probabilistic, event-oriented, R&D. CPM = Deterministic, activity-oriented, construction.
Common mistake
Mixing up CPM and PERT, and thinking CPM is for R&D work.
Correct answer: C) PERT is a method of statistically evaluating project duration over a time-sensitive domain.