Rationale Writing Guide
How to write rationale that holds up to SME and review board scrutiny.
Good rationale explains
- Why the requirement exists
- How it supports the parent requirement
- Applicable definitions
- Applicable standards or instructions
- Maintenance context
- Sustainment assumptions
- Interface context
- SME-confirmed explanation
- Why the requirement supports personnel, mission reliability, or service life
Do not
- Do not introduce inconsistent terminology.
- Do not imply ownership outside Ground Systems scope.
- Do not repeat the requirement without explanation.
- Do not use vague phrases such as "essential components" unless defined.
- Do not mention systems owned by Air Vehicle as if Ground Systems owns them.
Do Not Overstate Ownership
Rationale is read by reviewers across teams. Loose language can shift apparent ownership of aircraft systems to Ground Systems. Be deliberate.