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PAT-067 - SRR - Software Systems Requirements Milestone Review Checklist

AI (gpt-4o)

The Software Systems Requirements Review (SRR) exit criteria outlined in NASA-HDBK-2203, Topic 7.09, ensure that the software-related requirements derived from the system-level objectives are complete, consistent, achievable, and clearly documented. The SRR verifies that the software requirements align with mission objectives, system-level requirements, and stakeholder needs and provides a solid foundation for software design and development. Below is a summary of the Software SRR Exit Criteria:

Summary of Software SRR Exit Criteria

1. Requirements Completeness and Coverage:
   • All software requirements must be fully documented and complete, addressing functional, performance, interface, safety, security, reliability, and operational aspects.
   • The requirements must adequately cover all mission-critical and system-level needs.
2. Requirements Traceability:
   • Software requirements must be fully traceable to system-level requirements, mission objectives, and stakeholder expectations.
   • Requirements must also include bidirectional traceability, linking high-level system requirements to detailed software requirements and vice versa.
3. Interface Requirements:
   • All hardware/software interfaces, system interfaces, and external interfaces must be fully defined and documented.
   • Interface requirements must ensure compatibility with mission systems and external dependencies.
4. Feasibility and Risks:
   • Each software requirement must be assessed for feasibility given project constraints, such as cost, schedule, and available resources.
   • Risks associated with meeting the requirements (including overly complex or ambiguous requirements) must be identified and mitigation plans established.
5. Verification and Validation Planning:
   • The requirements must include measurable criteria that will allow for their verification and validation during later testing and development phases.
   • A preliminary verification and validation plan must be developed to demonstrate how compliance with requirements will be achieved.
6. Safety and Security Requirements:
   • All safety-critical and cybersecurity requirements must be explicitly defined, including requirements that address potential hazards, threats, and mitigations.
   • Safety analysis must confirm that the requirements adequately address mission-critical risk factors.
7. Consistency and Clarity:
   • Requirements must be clear, consistent, and free of ambiguities or contradictions.
   • Conflicts between requirements or ambiguities must be identified and resolved prior to design work.
8. Stakeholder Approval:
   • The requirements must reflect input from all relevant stakeholders—program management, systems engineering, safety assurance teams, and end-users—and receive formal approval.
   • Stakeholders must have reviewed and agreed upon the alignment between the system-level and software-level requirements.
9. Supporting Documentation:
   • Requirements documentation must be complete, reviewed, and approved. This includes the Software Requirements Specification (SRS), interface definitions, and any supporting analyses or matrices.
   • Supporting materials should ensure that requirements are readily accessible and understandable to all relevant teams.
10. Requirements Change Control Process:
    • Processes and tools must be in place for managing changes to requirements during subsequent development phases.
    • Change control procedures must address traceability, impact assessments, and mitigation for late-stage requirement modifications.

Key Purpose of Software SRR Exit Criteria

The SRR exit criteria ensure that the software requirements are properly defined and ready to proceed to the design phase. They aim to:

• Confirm that software requirements align with mission and system-level goals.
• Ensure requirements are clear, feasible, and traceable.
• Minimize risks due to incomplete or poorly defined requirements.
• Provide stakeholder confidence that the software development process is starting on a solid foundation.

Conclusion: Meeting the Software SRR Exit Criteria is essential to ensure the success of NASA projects. By achieving these criteria, the project team confirms that the software requirements are well-defined, complete, and consistent with mission objectives, allowing the development process to advance confidently to the design phase. This reduces the risk of late-stage issues and promotes efficient and effective software development.