Formal methods seek to contribute to the engineering of dependable systems by applying sound techniques based on computer science fundamentals. Complex systems often involve different formalisms to deal with the modeling of their different aspects, as each formalism is specific to only some system aspects and none is perfectly supporting all aspect constructs and their related semantics. Accordingly, different analysis techniques are required to check the different system views and verify different kinds of properties. Formalism integration is intended to support coherent specification and analysis of different aspects of a system. The FMi workshop aims at further research into hybrid approaches to formal modeling and analysis. It seeks contributions from researchers and practitioners interested in all aspects of integrating methods, either formal or semi-formal, for system development, covering all engineering development phases from user requirements through design and analysis techniques to tools. The workshop also encourages new initiatives of building bridges between informal, semi-formal, and formal notations. Authors are invited to submit both research and tool papers.