This book constitutes the refereed proceedings of the 6th International Symposium on NASA Formal Methods, NFM 2014, held in Houston, TX, USA, April 29 - May 1, 2014. The 20 revised regular papers presented together with 9 short papers were carefully reviewed and selected from 107 submissions. The topics include model checking, theorem proving, static analysis, model-based development, runtime monitoring, formal approaches to fault tolerance, applications of formal methods to aerospace systems, formal analysis of cyber-physical systems, including hybrid and embedded systems, formal methods in systems engineering, modeling, requirements and specifications, requirements generation, specification debugging, formal validation of specifications, use of formal methods in safety cases, use of formal methods in human-machine interaction analysis, formal methods for parallel hardware implementations, use of formal methods in automated software engineering and testing, correct-by-design, design for verification, and property based design techniques, techniques and algorithms for scaling formal methods, e.g., abstraction and symbolic methods, compositional techniques, parallel and distributed techniques, and application of formal methods to emerging technologies.

This book constitutes the proceedings of the 11th International Symposium on NASA Formal Methods, NFM 2019, held in Houston, TX, USA, in May 2019. The 20 full and 8 short papers presented in this volume were carefully reviewed and selected from 102 submissions. The papers focus on formal verification, including theorem proving, model checking, and static analysis; advances in automated theorem proving including SAT and SMT solving; use of formal methods in software and system testing; run-time verification; techniques and algorithms for scaling formal methods, such as abstraction and symbolic methods, compositional techniques, as well as parallel and/or distributed techniques; code generation from formally verified models; safety cases and system safety; formal approaches to fault tolerance; theoretical advances and empirical evaluations of formal methods techniques for safety-critical systems, including hybrid and embedded systems; formal methods in systems engineering and model-based development; correct-by-design controller synthesis; formal assurance methods to handle adaptive systems.