ABSTRACT
Though the etymology of “failure” is not entirely clear, it is
possibly derived from the Latin “fallere,” meaning “to
deceive.” The Webster dictionary defines failure as
“omission of occurrence or performance; or a state of
inability to perform a normal function.” It is not necessary
for the entire system to be non-operational for it to be
considered a failure. Conversely, a single “critical” com-
ponent failing to perform may result in the failure of the
entire system. For instance, a car headlamp malfunction
may or may not be considered a failure of the car; however,
the fuel injection system not working would be considered
so. The distinction exists because of the primary objective
of the system under consideration-that is, in the case of a
car it is seen as providing conveyance. Even among unsa-
tisfactory conditions it is a matter of degree. Similar dis-
tinctions apply when we define software failures. Is a bug a
failure? When does a bug become a failure?
