“It works” is one of Jerry Weinberg‘s nominees for the most ambiguous sentence in the English language.
To me, when people say “it works”, they really mean
of some feature
or some function
to meet some requirement
to some degree
based on some theory
and based on some observation
that some agent made
under some conditions
or maybe more.
One of the most important tasks for a tester is to question the statement “it works”, to investigate the claim, and to elaborate on it such that important people in the product know what it really means.
A Little Blog Post on a Big Idea: Does the Software Work? (Pete Walen)
Behavior-Driven Development vs. Testing (James Bach)
Perfect Software and Other Illusions about Testing (Jerry Weinberg)