

- Description
- Un grand cadran solaire au sol dans un parc, avec son style métallique incliné et ses heures en chiffres romains.
- Source
- Singlespeedfahrer · original page
- Licence
- CC0 Public domain
Planning and Estimation (PLA)
A date is a promise made to others; an estimate is a judgment under uncertainty. The greatest damage is not a wrong estimate (they all are, to some extent), but a wrong estimate…
Level: 🟢→🔴 · Code: PLA · Matrix: PI
Why this topic#
A date is a promise made to others; an estimate is a judgment under uncertainty. The greatest damage is not a wrong estimate (they all are, to some extent), but an estimate that is wrong and presented as certain: it triggers cascading commitments (user training, customer communication, resource freezes) that collapse together. A mature schedule does not predict perfectly; it states how reliably it predicts, and readjusts without drama.
What this topic measures#
- Axis: from imposed date to calibrated probabilistic forecasting.
- Key indicator: forecast reliability (share of commitments met on date, average gap between estimate and actual).
- Unit: % of commitments met; relative workload gap (± %); width of the announced range.
The five levels#
| Level | Short name | Promise | Typical indicator (orders of magnitude) |
|---|---|---|---|
| 1 | Imposed date | We know when we are asked to deliver; we discover along the way whether it is feasible. | Commitments met: < 30 to 40% |
| 2 | Milestone plan | A plan with milestones and owners exists; deviations are visible when they occur. | Commitments met: 40 to 60% |
| 3 | Shared estimation | The team estimates itself, with explicit margin and assumptions; the announced date is a range. | Met: 60 to 75%; workload gap ± 30% |
| 4 | Measured forecasting | Forecast reliability is measured on historical data and used to announce dates. | Met: 75 to 90%; workload gap ± 15 to 20% |
| 5 | Probabilistic forecasting | Dates are announced with a confidence level (“85% before the 15th”); the plan adjusts without surprises with each new piece of information. | Calibration: announced 85% ≈ observed 80–90% |
Milestones by level#
| ID | Milestone | Verifiable evidence |
|---|---|---|
| PI-PLA-1.1 | A target deadline exists for each project. | Date present in the project sheet. |
| PI-PLA-1.2 | Main tasks are listed. | List of work packages/deliverables. |
| PI-PLA-1.3 | Delay is identified (even late) and stated. | A past delay appears in meeting notes. |
| PI-PLA-2.1 | Plan with milestones, main dependencies, and owners. | Up-to-date planning diagram or table. |
| PI-PLA-2.2 | The plan is updated at least at each milestone. | Plan version history. |
| PI-PLA-2.3 | Known vacations and unavailability are integrated. | Plan cross-checked with the team calendar. |
| PI-PLA-3.1 | Estimates are made by those doing the work (poker, Delphi, decomposition). | Estimation workshop notes. |
| PI-PLA-3.2 | Each estimate includes its assumptions and a range or margin. | “Assumptions” and “min/max” fields completed. |
| PI-PLA-3.3 | External dependencies (other team, data, vendor) are planned with margin. | Dependencies listed with needed-by date and contact. |
| PI-PLA-3.4 | Actual capacity (excluding meetings, support, incidents) is used, not theoretical time. | Availability factor documented (for example 60 to 70%). |
| PI-PLA-4.1 | Estimated/actual gap is measured for each completed item. | Estimated/actual history over ≥ 20 items. |
| PI-PLA-4.2 | A throughput indicator (velocity, cycle time) feeds forecasts. | Throughput curve, cycle time (percentiles). |
| PI-PLA-4.3 | Announced dates are based on history, with a calculated range. | Dates with explained interval. |
| PI-PLA-4.4 | Rebaselines are counted and analyzed. | Number of replans tracked per project. |
| PI-PLA-5.1 | Probabilistic forecasts (Monte Carlo simulation on history or equivalent) are used. | Report with percentiles (50/85/95%). |
| PI-PLA-5.2 | Calibration is verified: announced 85% hits about 85 times out of 100. | Calibration table over ≥ 20 forecasts. |
| PI-PLA-5.3 | Decision-makers reason with ranges and not a single date. | Meeting notes citing ranges. |
| PI-PLA-5.4 | Each new piece of information (incident, departure) updates the forecast in under 2 days. | Update date vs event date. |
Detailed reading by level#
Level 1. Signs: the date comes from the sponsor or an external event; the team compensates with late nights. Benefit: alignment on a real deadline. Does not guarantee: feasibility or quality. Difficulty: 1/5. Effort: 1/5.
Level 2. Signs: milestone plan, updates before reviews. Benefit: shared view of the sequence. Does not guarantee: that the plan holds against unexpected events; estimation remains a wish. Difficulty: 2/5. Effort: 2/5.
Level 3. Signs: the team explains its estimates; the range is accepted as normal. Benefit: more honest commitments; less end-of-project stress. Does not guarantee accuracy. Difficulty: 3/5. Effort: 2/5.
Level 4. Signs: you know your error rate; you say “based on our history, 80% chance before end of March.” Benefit: credibility with sponsors. Does not guarantee stability if context changes (new tech, refreshed team). Difficulty: 4/5. Effort: 3/5.
Level 5. Signs: forecasts recalculated automatically, calibration verified, decisions based on percentiles. Benefit: informed portfolio decisions. Does not guarantee absence of black swans. Difficulty: 5/5. Effort: 4/5.
Partial achievement and rating#
Common rule: see README.
- 0.5: estimate made by the team but without written assumptions; history exists but is not used.
- 1: evidence can be reviewed without oral explanation.
- A partial 5: forecasts based on actual throughput (4.x acquired), simulation on one or two projects, calibration not yet measured (5.2 = 0). Score: about 4.2.
Datamart team, kit delivery every two months. History: 12 kits, median cycle time 18 days, 85th percentile 31 days. Announcement: “the fix will be delivered in the December kit, with 85% confidence before the 20th.” The department manager knows what to tell their teams.
Estimate turned into commitment. Symptom: the team systematically pads estimates. Cause: the estimate was used as a contract, and overrun was penalized. Remedy: separate estimate (judgment), target (wish), and commitment (decision), and write them separately.
Goodhart: if velocity is a target, it inflates (point inflation). Velocity is for team forecasting, never for comparing teams.
Estimates in person-days are biased by optimism (planning fallacy); the proven countermeasure is to estimate by analogy on comparable completed items (reference class forecasting) rather than by decomposition alone.
Move to the next level#
Possible means (optional)
- 1 → 2: a milestone plan in a shared tool; see planning tools.
- 2 → 3: collective estimation (poker, three-point), assumptions log; see Scrum in Practice and predictive methods.
- 3 → 4: collect estimated/actual, cycle time, percentiles; see metrics and reporting.
- 4 → 5: Monte Carlo simulation on history, calibration table, automatic recalculation.
AI can suggest a breakdown, flag forgotten tasks, and compare with similar items; it does not have access to your team's real context and its estimates are often too confident: treat it as one more opinion to calibrate against history. See AI for Project Management (General, Then Data).
See also#
- Related topics: 04 Scope · 05 Risks · 02 Governance · 09 Delivery.
- Other matrices: Lead Time and Industrialization (DataOps) (data) · Developer Experience and Flow (DL).
- Practice: Scrum in Practice · Predictive Methods (Waterfall, V-Model, Spiral, RUP, PMBOK, PRINCE2, Merise, CMMI) · Agile and Lean Methods (Manifesto, Kanban, XP, Lean, Shape Up, DSDM, SAFe, DevOps…) · Project Planning and Tracking Tools: Overview · Glossary.
✻ Written by Claude Sonnet 5.5