I think your colleague is very wrong here. The three things are NOT the same and have very specific definitions:
a FAILURE is what you see when the observed result of your test does not match the expected result
e.g calculator program:
Expected result: 29
observed result: 0.3333333
a FAILURE occured which produced an incorrect result.
The DEFECT is the thing that is wrong with the code. In the above example the programmer had coded the multiplication function to divide instead of multiply. This is the DEFECT in the code.
an ERROR is the thing that a human does when he or she codes (or designs) something incorrectly.
HUMANS make ERRORS which lead to DEFECTS which lead to FAILURES.
I would recommend not using the word FAULT for obvious reasons if you understand the above explanation.
<BLOCKQUOTE><font size="1" face="Verdana, Arial, Helvetica">quote:</font><HR>Originally posted by Govind: My colleague wants to know eact difference between Error, Defect and a Fault. She says these are used interchangebly.
Can someone throwlight ( my battery is down with heavy work)
Your colleague is correct that these ARE often used interchangeably.
They probably shouldn't be, though.