FASTEN is an open source environment for the specification, verification and assurance of critical systems. FASTEN is built with JetBrains' MPS and addresses different concerns:
requirements - textual specifications, natural language templates or mixing text and formal models;
design - different views over the architecture, high-level constructs for formal design based on NuSMV and Spin;
safety analyses - model-based safety analyses HARA, STPA, FMEA, HiP-HOPS, FT;
assurance arguments - use GSN, integrate with system and safety models, model confidence and deficits
For questions please send an email at: fasten-support at googlegroups dot com