Charter Section Deep-Dive
Milestones in a charter are not a calendar. They are the gates the project must pass through, with named criteria, named approvers, and named consequences if missed. The 5-to-7 rule keeps the gate discipline; named approvers keep the accountability; explicit criteria keep the project honest.
1. 5 to 7 milestones, no more
Above 7, the milestone list becomes a task list. Below 5, the project lacks gate discipline.
2. Each milestone has a named approver
If no one approves the milestone, it has not been reached. Approval defines completion, not the calendar.
3. Each milestone has explicit gate criteria
What evidence does the approver need to see? Without criteria, the approval becomes a vibe check.
4. Each milestone has a target date and a dependency
Targets without dependencies are wishful thinking. The dependency is the reason the milestone cannot happen earlier.
5. Milestones are outcomes, not tasks
"Design complete and signed off" is a milestone. "Hold design workshops" is a task. Tasks belong in the project plan, not the charter.
A 12-month software migration project with 5 milestones. Each has explicit criteria, a named approver, a dependency, and the consequence of missing the date.
Project: Aurora Pricing Engine Migration (legacy to cloud-native)
M1
Gate criteria: Functional requirements signed off by PM and Engineering Lead. Technical assessment of the legacy pricing engine documented. Migration approach (lift-and-shift vs rebuild) selected and justified. Initial backlog of 40-60 stories drafted.
Approver: Engineering Director (Sarah Chen)
Dependency: None (project start)
If missed: Build phase cannot start without approved approach. 4-week delay translates to USD 92K additional team cost.
M2
Gate criteria: At least one new pricing module live in production, behind feature flag at 5% traffic. SLOs met for 7 consecutive days. Observability dashboards live. Rollback procedure tested.
Approver: VP Engineering + SRE Lead (joint sign-off)
Dependency: M1 complete; staging environment provisioned (week 8)
If missed: Confidence in incremental migration approach broken. Recommend pause and replan if M2 slips past 31 Oct.
M3
Gate criteria: 50% of production pricing requests served by new engine with error rate at or below 0.1%. P95 latency at or below 250 ms. All 12 high-volume product lines migrated. Customer-facing rollback playbook tested in production.
Approver: VP Engineering + CTO
Dependency: M2 complete; vendor billing integrations live
If missed: Year-end go-live target at risk. Charter re-baseline conversation with Sponsor required.
M4
Gate criteria: 100% of production traffic served by new engine. Legacy engine running in shadow mode for cross-validation. No P0 or P1 incidents in 14 consecutive days. CFO sign-off on cost-tracking reconciliation (new engine within 5% of legacy run-rate).
Approver: VP Engineering + CFO + CTO
Dependency: M3 complete; cost-validation framework operational
If missed: Legacy engine decommissioning timeline slips. Each month of dual-running adds USD 38K infrastructure cost.
M5
Gate criteria: Legacy engine off. All hardware returned or reallocated. Code repository archived. Final post-implementation review presented to steering. Lessons-learned document published.
Approver: VP Engineering + Steering Committee
Dependency: M4 complete; minimum 90-day shadow-mode validation period
If missed: Project officially open beyond planned envelope. Sponsor decision required on extension vs reduced scope.
M1 ████ Discovery (8 weeks)
M2 ████ First mod (8 weeks)
M3 ████████ 50% routing (12 weeks)
M4 ████████████ 100% migrated (12 weeks)
M5 ████████████ Decom (12 weeks)
Jul 26 Sep 26 Dec 26 Mar 27 Jun 27
Cooper's Stage-Gate model maps cleanly to most charter milestone structures. The charter itself is the artefact for Stage 2 (Concept Definition); the milestone list is the gate structure for Stages 3 through 6.
| Stage | Artefact | Approver |
|---|---|---|
| Stage 1: Idea Screen | Project brief or one-pager | Manager or PM |
| Stage 2: Concept Definition | Project Charter (this document) | Sponsor |
| Stage 3: Build / Development | Sprint Reviews + Phase-gate review | Sponsor + steering committee |
| Stage 4: Testing and Validation | Test sign-off + acceptance criteria evidence | Sponsor + senior user / acceptance team |
| Stage 5: Launch | Launch readiness review + go / no-go decision | Sponsor + executive team |
| Stage 6: Post-Launch Review | Benefit realisation report at 3, 6, 12 months | Sponsor + benefits owner |
Source: Robert G. Cooper, "Winning at New Products", 5th edition (2017); PMI Standard for Program Management.
Calendar milestones instead of outcome milestones.
"End of Sprint 3" is a calendar event. "First production module live" is an outcome. Calendar milestones do not say whether the project is making progress.
Too many milestones (12+).
Becomes a task list. Sponsor stops attending steering because every meeting is a milestone review. Loses the gate discipline that milestones exist to enforce.
No named approver per milestone.
"Project team approves" means nobody is accountable. The first time a milestone is contested, the project has no resolution path.
Vague gate criteria.
"Design phase complete" with no criteria means the approver decides on the day, often based on calendar pressure rather than evidence. Charter approval becomes performative.
Milestones tied to deliverables not outcomes.
"Pricing engine code complete" is a deliverable. "Pricing engine processing 50% of production traffic with error rate under 0.1%" is an outcome milestone. Outcome milestones survive contact with reality.
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Updated 2 May 2026