The LNCS Transactions on Foundations for Mastering Change, FoMaC, aims to establish a forum for formal-methods-based research, dealing with the nature of today's agile system development, which is characterized by unclear premises, unforeseen change, and the need for fast reaction, in a context of hard-to-control frame conditions, such as third-party components, network problems, and attacks. Submissions are evaluated according to these goals. This book, the first volume in the series, contains contributions by the members of the editorial board. These contributions indicate the envisioned style and range of papers of topics covered by the transactions series. They cross-cut various traditional research directions and are characterized by a clear focus on change. .