Critical Path: The Few Tasks That Control Practical Completion
Critical path is not “the important tasks”. It is the chain of activities that, if delayed, moves the finish date. Understanding it changes how you allocate resources and how you win time claims.
1. Key Concepts (Builder-Friendly)
- Float: time an activity can slip without moving completion.
- Zero float: the task is critical (in that program logic state).
- Near-critical: small float; often becomes critical after minor delays.
2. Protecting the Critical Path
- Resource priority: staff and plant go to critical tasks first.
- Procurement priority: long-lead items that feed critical tasks are treated like emergencies.
- Interface priority: eliminate rework at interfaces on critical sequences (e.g., waterproofing → screed → tiles).
3. EOT Reality
Many EOTs fail because the delay did not affect the critical path at the time. The evidence usually required is a baseline program, regular updates, and clear demonstration of impact to the controlling sequence.
4. What Builders Should Capture Week-to-Week
- Baseline + updates: keep PDF snapshots of the baseline and each update (date-stamped).
- Controlling sequence narrative: write a short note: “what is driving completion this week?”
- Constraints log: approvals, drawings, selections, inspections, deliveries—what is threatening the path?
- Evidence: photos and diaries tied to specific activities (not generic “rained today”).
5. Common Critical Path Mistakes
- Over-constraining: too many date constraints hide reality. Use logic links and let the program calculate outcomes.
- Missing procurement: if joinery lead time isn’t in the program, the program is lying.
- Ignoring commissioning: “handover” is not a single task; commissioning and certification are sequences.