The selection and assignment of reviewers to project proposals is a crucial task for funding institutions, ensuring fair and accurate evaluations by competent reviewers. However, determining the most qualified reviewers can be challenging. This paper introduces a new methodology for calculating a reviewer competency score, derived from a weighted combination of the h-index, academic title, and past evaluation performance of reviewers. The methodology integrates similarity-based approaches from group decision-making literature with knowledge rules to assess the past evaluation performance of reviewers. This approach aims to enhance the reviewer assignment process by ensuring proposals are reviewed by highly qualified and experienced experts. An empirical analysis involving 575 reviewers and 8808 evaluations from a regional development agency demonstrates the effectiveness of this methodology. Adaptable to various evaluation contexts, including academic journals and conference management systems, this method provides a robust tool for improving reviewer selection and assignment. Future research will focus on developing assignment models that incorporate this competency score calculation to maximize reviewer-proposal matching quality