5. device-B
The definitions of fault, error, and failure
5
device-A
function
Imagine there’s a device (A) which provides some function to
another device (B).
device-B
device-A function
There are several parts inside the device-A. Some of the statuses
of them should be observable from outside by some means.
parts
observable
device-B
device-A Failure
A “fault” means some abnormal condition of a parts,
an “error” means the condition observed from outside,
a “failure” means the malfunction caused by the fault.
Fault
Error