Numerous stakeholders collaborate to develop system requirements for a complex system. They conceive needs, evaluate risk, cost and benefits, identify tradeoffs, and negotiate priorities over a long period of time. Government and industry need a structured approach to requirements elicitation that supports this collaborative effort. Automated support is a long term goal of the author's research. The initial goal is to develop a firm foundation for capturing requirements, analyzing them, and supporting different views, including capture views (e.g. capabilities, constraints, operational environment), domain views (e.g. tracking, manufacturing, reliability), and stakeholder views (e.g. user, customer, designer, tester). These views help the analyst review specifications for errors and omissions. The paper identifies capture views and provides details concerning the system capabilities view, which includes functions, behavior, information entities, and non-functional requirements.