WhenMathMulti-Phase Deadline Planner
Give each phase a duration and the phases it depends on. Parallel phases with no shared dependency run at the same time, and the finish date is driven by whichever chain of phases is actually the longest, the critical path.
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Worked example
Design, at 2 days, and Content, at 5 days, both start at project kickoff and run in parallel, with Launch, at 1 day, depending on both of them finishing first. The project finishes 6 calendar days after kickoff, driven entirely by the 5-day Content phase plus the 1-day Launch phase after it. Design has 3 days of slack in this plan and is not on the critical path, so shortening Design alone, from 2 days down to 1, would not move the finish date at all.
Common mistakes
- Assuming every phase is "critical" just because it appears on the plan. Only phases with zero slack, highlighted in the receipt, actually move the finish date if they slip.
- Shortening a phase that has slack, expecting the project to finish earlier. Only shortening a phase on the critical path actually pulls the finish date in.
Limitations
Durations are fixed numbers entered directly, not estimates carrying any uncertainty. This is a planning model, not a probabilistic project-management tool that accounts for risk or variance.
Frequently asked questions
- What happens if I create a dependency cycle?
- The calculator detects it and reports an error rather than guessing an order, since a cycle has no valid schedule.
- Can I export this as a calendar?
- Yes, use Download .ics to get a milestone for each phase's finish date, importable into most calendar apps.