What is a Black Box

[Andrews]

Black box

What does "Black box design" mean ?
I found this terminology in the PPAP manual under FORD specific requirement.

 

[Marc]

An example of a 'black box' would be an assembly. Take a radio. The auto company wants something to play sound but doesn't care about the guts. In short the customer (auto company) is buying something which does something but the customer doesn't care how it does it (it's internal design).

Others?