One needs to understand what competence is first. For that, Quan Com and TTA are good reference/reading materials. Quan Com is actually one of the most popular models, initiated in the healthcare sector.
Converting Subjective Opinion to Objective Data
Next, we need to convert subjective/expert opinion into objective data, i.e., through BARS. This method is used everywhere, be it competence designing or environmental impact assessment.
I am a "certified performance and competence developer" from CAMI; this is the best way I can suggest. Once you are through, I can help by reading your definitions/chosen competencies to determine if they are right or not.