ITPEC FE Morning April 2019 Question 51

Critical Path & PERT Diagram — Evaluating the effect of removing or delaying activities on project duration.

All paths from start to end:
- A→C→G: 2+2+4 = 8
- B→F→G: 4+4+4 = 12 (critical path)
- B→D→H: 4+2+5 = 11

The critical path is B→F→G = 12 days.

The correct answer is c): When activity F becomes unnecessary, the project will end 1 day earlier.

Without F, the remaining paths are A→C→G (8) and B→D→H (11). The new critical path becomes 11 days — a reduction of exactly 1 day from the original 12.

Why not the others:
- a) A–C–G = 8 days, not the critical path
- b) The project requires 12 days (not 11)
- d) A 2-day delay on H makes B→D→H = 13, changing the project from 12 to 13 — only a 1-day delay, not 2

Key rule: Removing an activity from the critical path shortens the project only by the difference between the old and new critical path lengths. A delay on a non-critical activity causes project delay only if it exceeds that activity's float.

AI-generated — may contain errors