Staff apply the skills their work needs and keep them current through continuing professional development. The level rises from demonstrating required skills and seeking new ones (level 1), through sound knowledge of needs and priorities in one's area and transferring skills to others (level 2), to providing solutions and answering technical queries while coaching colleagues (level 3), up to being recognised as a reference expert across the Organization, engaging in advanced research and setting best practice that positions WHO (level 4).
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.