Critical path
The critical path is the longest chain of finish-to-start dependencies through your schedule. Tasks on the critical path have zero float — any slip to any of them pushes the overall end date. Tasks off the path have some slack; they can slip a little without affecting the delivery date.
Turn on critical path highlighting when you’re near a deadline and want to know exactly which work is load-bearing.
Turn on critical path highlighting
Section titled “Turn on critical path highlighting”- Open the Gantt for your lens.
- In the Gantt toolbar, open Display Options.
- Enable Critical path.
- Bars and dependency arrows on the critical path render with a highlighted treatment, making the chain pop out against the rest of the schedule.
Toggle the option off when you no longer need the highlight.
How Foundation computes it
Section titled “How Foundation computes it”Foundation runs the standard Critical Path Method (CPM) algorithm on your lens:
- Gather leaf tasks with both a start and end date.
- Follow finish-to-start dependencies only. SS, FF, and SF links are intentionally excluded from the CPM analysis — they don’t represent a classic precedence chain.
- Forward pass — compute Early Start and Early Finish for each task.
- Backward pass — compute Late Start and Late Finish.
- Flag zero-float tasks — those where Late Start equals Early Start are on the critical path.
If your lens has no FS dependencies between dated tasks, there is no critical path to show.
What the highlight tells you
Section titled “What the highlight tells you”- A highlighted task is on the current critical path. Slipping it delays the project.
- A non-highlighted task has slack. It can move a bit without changing the overall end date.
- When you change dates or dependencies, the critical path recomputes. A task that was critical may drop off; one that wasn’t may come on.
Use the critical path to focus
Section titled “Use the critical path to focus”- In a stand-up: ask about critical tasks first. Slippage elsewhere is less urgent.
- Before a deadline: ensure every critical task has an owner, has recent progress, and has realistic dates.
- When triaging blockers: blockers on the critical path are higher priority than blockers off it.
- Shortening the path: compress duration on critical tasks (crashing) or run them in parallel where possible (fast-tracking).
Gotchas
Section titled “Gotchas”- Only FS links feed the algorithm. If a key relationship in your lens uses SS or FF, Foundation won’t treat it as critical even though it may be in practice.
- Tasks without both dates are excluded — a missing date is effectively invisible to CPM.
- Groups are not analyzed; only leaf tasks are evaluated.