Ranged estimation gives your project schedule a realistic window instead of one fixed date. Learn how to apply PERT, risk, and uncertainty in 5 steps.
Ranged estimation
Ranged estimates compare logged progress against the initial forecast, making estimates better than ever before.
Ranged estimates give each task a best-case and worst-case duration instead of a single fixed number. That range flows into your schedule, so finish dates are predicted as a window rather than a false-precision point-in-time. The result is a plan that admits what it doesn't know, and gets sharper as real work rolls in.
Uncertainty is inevitable
Forecasting exactly how long every item in a work breakdown structure will take is impossible. Uncertainty in project work is constant, and fixed schedule dates with finite durations belong to a planning era that never really worked.
Teams underestimate their own work
People are optimistic, and they hand in low fixed estimates because they don't want to disappoint managers. Framing forecasts as best-case and worst-case ranges takes that pressure off. Logged progress can then be compared against the initial forecast of effort, so estimating gets better over time. Change history is captured from portfolio level down to individual team members and task detail.
Best-case to worst-case ranges
A ranged estimate, for example 3 to 5 days, accounts for uncertainty in the plan from the start and is visible in every schedule bar. The wider the white bar, the more uncertainty left to wrangle. Ranges let the scheduling engine surface that uncertainty before it becomes a problem downstream.
Statistically correct schedules
Because estimates are entered as a range, finish dates are predicted as a range too: Expected Finish (best case) to Latest Finish (worst case). Ranges are set on assignments, which roll up to the task. Task estimates roll up to the project and package to build the schedule. It's a statistically correct roll-up that uses probability to weigh one outcome against another, factoring in everything else moving through the portfolio.
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