Model-based requirement generation

Model-based systems engineering (MBSE) is intended to enhance productivity and quality through a paradigm shift from document-centric engineering. However, most MBSE development tools require the manual creation of requirement constructs. This time consuming step is vulnerable to human error, and must be repeated as high-level designs inevitably evolve. This paper describes a capability that uses SysML structure and behavior diagrams to automatically generate textual requirements. Using modified off-the-shelf MBSE software, information is extracted from SysML constructs (e.g., blocks, states, activities) and combined in SysML requirement objects. The requirement syntax conforms to NASA and DoD standards. Requirements are based on SysML construct relationships (e.g., allocations, control flows, object flows) commonly used in diagrams to describe system architectures and designs. Through the embedded error checker, designers can ensure that requirements are complete and consistent. When new requirement constructs are created, traceability to the “parent” SysML constructs is automatically created to capture the rationale. As the architectural models evolve, the requirements are updated to ensure consistency with configuration management and other model-based tools. Such an approach allows designers to quickly assess the impact of requirement changes and reduces requirement management costs. The capability is demonstrated by comparing model generated requirements to a traditionally developed GPS receiver specification.