The optimistic time estimate is defined as :
- AThe best guess of the minimum time that would be required to complete the activity.
- BThe best guess of the maximum time that would be required to complete the activity.
- CThe shortest possible time in which an activity can be completed, under ideal conditions.Correct
- DThe longest possible time in which an activity can be completed, under any conditions.
Solution
Concept
Three time estimates in PERT
Step-by-step solution
1. Optimistic time (t₀): shortest possible time if everything goes well. 2. Most likely time (tL): the most probable time. 3. Pessimistic time (tp): the longest time, when everything goes wrong.
Explanation
In PERT the optimistic estimate is the minimum time in which the activity can be completed under ideal conditions, and the pessimistic estimate is the maximum time under adverse conditions.
Why the other options are wrong
(b) and (d) describe the pessimistic time. (a) is loosely worded as a "best guess"; the standard definition of optimistic time is the shortest possible time under ideal conditions.
Shortcut
Optimistic = shortest possible; pessimistic = longest possible.
Common mistake
Choosing (a) because it also mentions the minimum time.
Correct answer: C) The shortest possible time in which an activity can be completed, under ideal conditions.