Towards the Co-evolution of Models, Code, and Assurance Cases: The CAID Framework

Model-based software development is rarely performed with models only, and not everything is generated from the model(s). Handcrafted source code, documentation, simulation, data, tests, and assurance cases are the obvious (but not the only) examples. These artifacts, just like models, are version controlled, but kept in various, disjoint repositories. As they are often dependent on each other, the challenge is to maintain and manage the consistent co-evolution of such artifacts in the context of an agile development process. Some of the artifacts are related to software assurance - the construction of logical arguments, called assurance cases, that demonstrate why the software (or system) is safe and performant - which need to be continuously revised and updated in a deadline-driven development process. The Continuous Assurance-Integrated Development tool framework has been constructed to address the challenge stated above. The framework integrates and links together various software engineering artifacts: models, source code, documents, assurance cases, etc. and provides dependency tracking and change management functions. The framework is based on an open server-database/client-adapter architecture, where various repositories can be interwoven. A prototype of the framework has been created that integrates git repositories, a model database, and assurance case documents. The prototype has been published under an open source license.