With complex systems and complex requirements being a challenge that designers must face to reach quality results, multi-formalism modeling offers tools and methods that allow modelers to exploit the benefits of different techniques in a general framework intended to address these challenges. Theory and Application of Multi-Formalism Modeling boldly explores the importance of this topic by gathering experiences, theories, applications, and solutions from diverse perspectives of those involved with multi-formalism modeling. Professionals, researchers, academics, and students in this field will be able to critically evaluate the latest developments and future directions of multi-formalism research.