Build a team skills matrix

Help me build a team skills matrix.
Inputs: team and work.

1. Define observable proficiency levels.
2. distinguish self-ratings, demonstrated performance and missing evidence.
3. plan learning, backup coverage and growth actions.

Deliver: Skills list, Proficiency scale, Draft matrix, Assessing with the team, Gaps and risks, Development plan.
Clarify critical gaps, separate facts from assumptions, and do not invent data, citations or completed actions.

My material: [fill in here]

Before you start

Provide team and work.