14/05/2026
Late-stage engineering changes are rarely difficult because of engineering alone.
They become difficult because of timing.
Early in development:
• options remain open
• system impact is limited
• changes are manageable
Later in CS-23 projects:
• testing has already started
• documentation has reached high maturity
• certification evidence is progressing
At that stage, even small modifications can propagate through the entire development and certification system.
The technical solution itself may remain simple.
But:
• proving compliance becomes harder
• validation scope expands
• project cost increases disproportionately
This is why late-stage changes are rarely only engineering decisions.
They become coordination problems across design, testing, validation, and certification.
We expanded this topic further here:
https://faaw.cz/insights/late-stage-changes
