Three different views of the same work are combined instead of asserting a mean without context. Uncertainty becomes a planning range and expectation. The approach is useful when buffers and risk need a clear rationale.

1. 1

   Scope

   Estimate frame

   

   Goal

   Estimate frame: Define work, unit, Done, and included risks unambiguously.

   Inputs for this step

   • Close work package, unit, Done criterion, and dependencies; define O, M, and P as scenarios rather than target values.
   • Clear scope, historical analogies, O/M/P scenario sheet, calculation sheet, and assumption log

   Actions

   • Define work, unit, Done, and included risks unambiguously.

   Output

   Estimate frame

   Define work, unit, Done, and included risks unambiguously.

   Quality check

   Do all three values describe the same completed work?

   Pitfall

   Optimistic estimates less scope than pessimistic. Close scope once and vary only conditions between scenarios.

   Timing: 5–10 minutes

2. 2

   Scenarios

   Three values

   

   Goal

   Three values: Derive O, M, and P from concrete conditions and analogies; verify O ≤ M ≤ P.

   Inputs for this step

   • Estimate frame

   Actions

   • Derive O, M, and P from concrete conditions and analogies; verify O ≤ M ≤ P.

   Output

   Three values

   Derive O, M, and P from concrete conditions and analogies; verify O ≤ M ≤ P.

   Quality check

   Are extremes plausibly reachable rather than perfect/worst imaginable?

   Pitfall

   P is doubled without naming a scenario. Record conditions, evidence, and trigger for each value.

   Timing: 10–20 minutes

3. 3

   Calculate

   Expected value

   

   Goal

   Expected value: Compute triangular expected value E=(O+M+P)/3 and preserve the range separately.

   Inputs for this step

   • Three values

   Actions

   • Compute triangular expected value E=(O+M+P)/3 and preserve the range separately.

   Output

   Expected value

   Compute triangular expected value E=(O+M+P)/3 and preserve the range separately.

   Quality check

   Is the formula visible and calculated in one unit?

   Pitfall

   Expected value 9 is treated as a certain commitment. Report the value with O–P range and assumptions.

   Timing: 5–10 minutes

4. 4

   Drivers

   Uncertainty view

   

   Goal

   Uncertainty view: Inspect M→P and O→M gaps for dominant uncertainty and controllable actions.

   Inputs for this step

   • Expected value

   Actions

   • Inspect M→P and O→M gaps for dominant uncertainty and controllable actions.

   Output

   Uncertainty view

   Inspect M→P and O→M gaps for dominant uncertainty and controllable actions.

   Quality check

   Is the broad interval linked to a concrete driver?

   Pitfall

   The range remains without a learning step. Prioritise the costly uncertainty driver and assign evidence work.

   Timing: 5–10 minutes

5. 5

   Use

   Planning range

   

   Goal

   Planning range: Use the estimate for a named decision and schedule review after scope or evidence changes.

   Inputs for this step

   • Uncertainty view

   Actions

   • Use the estimate for a named decision and schedule review after scope or evidence changes.

   Output

   Planning range

   Use the estimate for a named decision and schedule review after scope or evidence changes.

   Quality check

   Is it clear how value/range will be used and when to re-estimate?

   Pitfall

   E is added to a date without dependencies. Model calendar forecast separately with dependencies, capacity, and risk.

   Timing: 5–10 minutes