Precedence tables and directed activity networks; Dummy links when using activity-on-arrow representation; Forward/backward scans; Minimum completion, critical path, earliest/latest starts and slack; Delay/reduction effects and contextual limitations
Example 1
Activities: A(6) first; B(5) and C(7) follow A; D(2) follows both B and C. Durations are days. Find the project duration.
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Answer: 15
- The critical route is A–C–D, the longer dependency chain.
Example 2
Activities: A(2) first; B(5) and C(7) follow A; D(3) follows both B and C. Durations are days. Find the earliest start of D.
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Answer: 9
- D must wait for both predecessors, so use the later finish.
Example 3
Activities: A(2) first; B(5) and C(7) follow A; D(4) follows both B and C. Durations are days. Find total float/slack for B.
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Answer: 2
- B can take two extra days without delaying D, because C finishes two days later.