This book constitutes the proceedings of the Third Enterprise Engineering Working Conference (EEWC), held in Luxembourg during May 13-14, 2013. EEWC aims at addressing the challenges that modern and complex enterprises are facing in a rapidly changing world. The participants of the working conference share a belief that dealing with these challenges requires rigorous and scientific solutions, focusing on the design and engineering of enterprises. The goal of EEWC is to stimulate interaction between the different stakeholders, scientists as well as practitioners, interested in making enterprise engineering a reality.The eight papers presented at the conference were carefully reviewed and selected for inclusion in the book. EEWC 2013 had 24 submissions and accepted eight for publication. The topics of the presented papers allowed for active participation in interesting discussions and exchange of ideas and stimulated future cooperation among the participants. This made EEWC a real “working conference� contributing to the further development of enterprise engineering as a mature discipline. The topics covered include value orientation, enterprise change, and engineering requirements and entropy issues.