TYPO3 Upgrade Effort Model

Generic effort estimation model for TYPO3 LTS major version upgrades. Captures what makes an upgrade hard (per-version breaking-change deltas, Rector coverage, ecosystem readiness); your team's historical data captures how fast you handle each unit.

Calibration is intentionally external. The model gives per-extension hour ranges; you supply the multiplier from your own projects.

When to Use

• TYPO3 upgrade estimation: "v13 → v14.3 LTS effort?"
• Extension compatibility: "Which extensions need updates for v14?"
• Skip-version vs incremental decisions

v14.3 LTS Headline

The largest breaking-change cycle in years — 98 breaking + 31 deprecation entries, all in v14.0. Sprint 14.0–14.2 are unsupported.

Most impactful v14 multipliers (full table in references/risk-multipliers.md):