"The Practice of Enterprise Modeling" is a professional book that addresses the increasing importance of Enterprise Modeling (EM) in both academic and practical realms. It provides a comprehensive overview of various methods, approaches, and tools of EM that are used for different purposes, including the development of business strategies, the restructuring of processes, and the alignment and governance of business and IT architectures. The book is based on the results of PoEM 2009, a conference that brought together researchers, practitioners, and users to enhance the understanding and practice of EM. The selected contributions reflect the diversity of topics in EM, encompassing both human and organizational aspects as well as technical issues related to the development of information systems. The thematic sessions of the program offer valuable insights into the experiences and challenges in the field of Enterprise Modeling.