Human Resources Management (HRM) is the strategic management of the employees, who individually and collectively contribute to the achievement of the strategic goals of an organization. Most HRM tasks are based on acquiring the right information and reasoning about skills and competencies of individuals. In this paper we present a formal ontology for competency management and consider three reasoning problems related to HRM, namely, determining the set of skills of an individual, conducting competency gap analysis, and determining whether an individual satisfies a set of requirements.