Ontology-Based Competency Management for Corporate E-Learning 311 Copyright © 2007, Idea Group Inc. Copying or distributing in print or electronic forms without written permission of Idea Group Inc. is prohibited. Chapter XV Ontology-Based Competency Management for Corporate E-Learning Fotis Fraganidis, University of Athens, Greece Greogoris Mentzas, University of Athens, Greece Abstract The synergies between ontology management, competency management, and e-learning have been explored during recent years both on theoretical and practical levels. This chapter describes the architecture, design, and deployment of a system that integrates ontologies with competency management and e-learning, as well as with other human resources functions. Moreover, a detailed description of the supportive methodology and the main lessons learned in technical and organisational areas are presented. This system currently is being deployed for research purposes in a national subsidiary of Microsoft, the information technology (IT) services multinational frm. The objective of this chapter is to provide the reader with an overview of the key concepts in competency-based management, a non-technical methodol- ogy for supporting the effective deployment of an ontology-based competency management system and an analysis of the lessons learned during the frst deployment phase.