PAT-072 - CDR - Software Critical Design Milestone Review Checklist

AI (gpt-4o)

The Software Critical Design Review (CDR) exit criteria outlined in NASA-HDBK-2203, specifically in Topic 7.09, are key checkpoints to ensure the software design is mature, meets project requirements, and is ready to move into implementation and testing phases. These exit criteria serve to verify the completeness, correctness, and readiness of the software design while assessing risks before proceeding further. Below is a summary of the Software CDR exit criteria:

Summary of Software CDR Exit Criteria

1. Requirements Traceability:
   • All software requirements should be fully traceable to system-level requirements, design documentation, and safety/mission assurance plans.
   • This includes verifying alignment with software interfaces, performance parameters, and operational constraints.
2. Design Maturity and Completeness:
   • The software design must be demonstrated to meet all functional and non-functional requirements.
   • Design artifacts (e.g., architecture diagrams, design specifications, data flow diagrams, and interface designs) must be complete, reviewed, and approved.
   • Any design trade studies must be finalized and documented.
3. Interface Consistency:
   • All external (system-level) and internal (software module-level) interfaces should be defined, documented, and confirmed for compatibility and correctness.
4. Risk Management:
   • Identified risks associated with the software design should have appropriate mitigation plans documented and tracked.
   • Any design issues or open items flagged during earlier reviews should be closed or have clear paths to resolution.
5. Testing and Verification Plans:
   • A complete software testing and verification plan, including unit testing, integration testing, system testing, and acceptance testing, should be defined.
   • Test cases and scenarios for validating design should align with requirements and mission objectives.
6. Software Safety Assurance:
   • Safety-critical software components must meet established safety requirements, and associated hazards must be mitigated and documented.
   • Compliance with standards like NASA-STD-8739.8(Software Assurance Standard) or relevant safety standards must be verified.
7. Configuration and Quality Management:
   • Configuration control must be in place to manage the development and design baselines.
   • Quality assurance processes, including peer reviews and inspections, should be demonstrated to be in compliance with project and agency standards.
8. Feasibility for Implementation:
   • The design should be assessed as technically feasible for development, given the project's resources, schedule, hardware constraints, and tools.
   • Hardware/software compatibility and performance under expected conditions must be verified.
9. Documentation Completeness:
   • All CDR deliverables, including design documents, schematics, code prototypes (if any), and associated analyses, must be complete, reviewed, and formally approved.
10. Readiness to Proceed:
    • The project team must demonstrate readiness to transition the design into detailed implementation, coding, and integration phases with minimal unresolved issues.
    • All action items from the CDR should be addressed with follow-up plans defined for any deferred items.

Key Purpose of Software CDR Exit Criteria

The Software CDR exit criteria ensure that the design phase wraps up without critical gaps or unresolved issues, reducing the risk of downstream problems like coding errors, testing failures, or delays. Meeting these criteria gives stakeholders confidence that the software design:

• Is robust and well-documented.
• Adheres to requirements and project goals.
• Is safe and reliable for deployment.
• Is adequately prepared for implementation and testing phases.

By meeting these exit criteria, NASA projects can ensure a smooth and risk-managed transition from Critical Design Review into software development and integration.