This study explores the issues in the development and application of a competency model and provides implications for more precise integration of competencies into human resource (HR) functions driving performance improvement. This research is based on a case study from a Korean consumer corporation. This study employed document reviews, observation, and interviews. Although competency modeling is time-consuming work, this study's results found that it can be a helpful intervention tool for improving HR performance in several ways. Furthermore, the results identified critical issues for success in each aspect of competency modeling. This article offers practical and useful insights into the relationship between competency modeling and HR performance improvement. (Contains 3 tables and 1 figure.)