We got this idea from Toyota in how to assess competency and development of technicians. It is called the "Harvey Ball". You need to first define each skill requiring competency assessment to perform the technician role. The four quadrants are:
No quadrant - No exposure to competency
1st quadrant - Exposure to competency by watching a senior tech doing the work
2 quadrants - Can do the work under close supervision
3 quadrants - Can do the work without supervision
4 quadrants - Has been objectively/formally/hands-on assessed or tested to having the competency.
We break the technician role and define each skill required, what their current status, and then creating a path for their development that meets the skill needs of the company.
With respect to soft skills (like customer service, motivation,...) the Harvey ball doesn't work. We find defining what "meets expectations", "exceeds expectations", and then "does not meet expectations" helpful in giving good feedback to technicians in development.
These tools help communicate to new employees how to understand their compensation and how they can improve their performance and accountable for their own development.