BSE TECHNICAL NOTE
When Exact Parts Disappear: A Controlled Alternate-Source Method
An alternate should not be treated as equivalent merely because it fits physically or has a similar description.
The evaluation should consider electrical, mechanical, environmental, software/firmware, documentation and lifecycle implications relevant to the application.
The practical routes are usually exact replacement, approved alternate, repair/overhaul, or functional replacement/redesign.
Practical checklist
- Confirm the exact identity
- Determine why the exact source is unavailable
- Define equivalence criteria
- Compare four response routes
- Document deviations before approval
Application note: This public guidance is intended to improve requirement quality. Final technical, contractual and compliance decisions remain specific to the project and end-user criteria.