The article describes the validation chain as a system for reducing defect leakage rather than as a linear checklist. Each level catches certain issue classes more efficiently, so the real engineering challenge is to prevent information loss between them.
That is why entry criteria, coverage transfer, regression frequency, and issue-closure rules matter so much. They may look procedural, but they directly shape how well a program learns before field exposure increases the cost of mistakes.
“Explanation of which issue types fit which validation level”
The weekly regression-cut example is included to show how teams can stay controlled even when time pressure would otherwise push them into shallow pass/fail thinking.
This subject can be extended further with examples from different development-maturity situations.
