PERT vs. CPM orientation: Which statement correctly distinguishes the orientation of PERT and CPM techniques?
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AProgramme Evaluation and Review Technique (PERT) is event-oriented
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BProgramme Evaluation and Review Technique is not event-oriented
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CCritical Path Method (CPM) is event-oriented
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DCritical Path method is event oriented.
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EBoth PERT and CPM are purely cost-oriented
Answer
Correct Answer: Programme Evaluation and Review Technique (PERT) is event-oriented
Explanation
Introduction / Context:PERT and CPM are classic network-based planning tools. Understanding their focus helps practitioners select the right tool for uncertain R&D-type projects vs. repetitive construction with known activity durations.
Given Data / Assumptions:
- PERT uses probabilistic time estimates and focuses on events (milestones).
- CPM uses deterministic durations and focuses on activities and their costs.
- Both depict logic but differ in emphasis and data requirements.
Concept / Approach:PERT charts were historically 'event-oriented,' indexing nodes as events and computing expected times using optimistic, most likely, and pessimistic estimates. CPM, developed for construction/maintenance, is activity-oriented with cost–time trade-off (crashing) emphasis.
Step-by-Step Solution:Identify PERT: events (nodes) mark the completion of preceding activities; uncertainty modeled with beta assumptions.Identify CPM: activities (arrows/bars) with deterministic durations; cost-curves enable crashing.Therefore, the correct distinguishing statement is that PERT is event-oriented.
Verification / Alternative check:Most textbooks contrast Activity-on-Arrow PERT diagrams (event emphasis) with Activity-on-Node CPM diagrams (activity emphasis), even though modern software often uses AON for both.
Why Other Options Are Wrong:
- Options B, C, and D contradict standard definitions.
- Option E is incorrect: CPM includes cost optimization; PERT focuses on time under uncertainty, not cost.
Common Pitfalls:Assuming PERT and CPM are interchangeable; ignoring that risk buffers and three-time estimates are central to PERT but not CPM.
Final Answer:Programme Evaluation and Review Technique (PERT) is event-oriented