Novice
Heuristics are used superficially to evaluate either the existing design, competitors, or the presented design. The inclusion of heuristics does not add much value to the quality of design decisions.
Competent
Heuristics have been used to evaluate and identify clear usability issues, at least some of which are then addressed in the final design presented.
Proficient
Heuristics have been used to identify opportunities in the existing product (if available) as well as opportunities based on competitive and comparable products. The final product has taken all of these findings into account, and has also been through a final evaluation to maximize quality of output.
Expert
Multiple evaluators have participated in a review, with clear actions taken to address issues surfaced. Findings and actions have also been prioritized and developed into a rollout plan.