Approved vendor list (AVL/AML)
also: AVL · AML · approved manufacturer list
The list of manufacturers and part numbers approved for each line of the BOM, so buyers and factories know exactly which substitutes are allowed.
For each BOM line, the AVL or AML names the specific manufacturer part numbers that have been qualified, meaning tested and approved in your product. Contract manufacturers should buy only from that list unless you approve a change in writing.
A good AVL defends against two opposite problems: being stuck when the only approved part is unavailable, and quietly receiving an "equivalent" that behaves differently (a capacitor that loses value with temperature or voltage, a regulator with different stability).
Generic parts such as resistors and many capacitors can usually have broad alternates. Chips, connectors, displays, batteries and anything covered by a safety certification usually cannot be swapped without re-validation, and sometimes re-certification.
Founder takeaway
Approve at least two sources for every line where practical, and require written approval for any substitution outside the list.
engineer review pending