Why test?
The following example illustrates why software testing is so important:
Taken from http://techiecorner.blogspot.com .
In March 1992, a man living in Newtown near Boston, Massachusetts, received a bill
for his as yet unused credit card stating that he owed $0.00. He ignored it and threw
it away.
In April, he received another and threw that one away too.
The following month, the credit card company sent him a very nasty note stating they
were going to cancel his card if he didn't send them $0.00 by return of post. He called
them and talked to them; they said it was a computer error and told him they'd take
care of it.
The following month, our hero decided that it was about time that he tried out the
troublesome credit card figuring that if there were purchases on his account it would
put an end to his ridiculous predicament. However, in the first store that he produced
his credit card in payment for his purchases, he found that his card had been
canceled.
He called the credit card company who apologized for the computer error once again
and said that they would take care of it. The next day he got a bill for $0.00 stating
that payment was now overdue. Assuming that, having spoken to the credit card
company only the previous day, the latest bill was yet another mistake, he ignored it,
trusting that the company would be as good as their word and sort the problem out.
The next month, he got a bill for $0.00 stating that he had 10 days to pay his account
or the company would have to take steps to recover the debt.
Finally giving in, he thought he would play the company at their own game and
mailed them a cheque for $0.00. The computer duly processed his account and
returned a statement to the effect that he now owed the credit card company nothing
at all.
A week later, the man's bank called him asking him what he was doing writing a
cheque for $0.00. After a lengthy explanation, the bank replied that the $0.00 cheque
had caused their cheque processing software to fail. The bank could now not process
ANY cheques from ANY of their customers that day because the cheque for $0.00
was causing the bank's computer to crash.
The following month, the man received a letter from the credit card company
claiming that his cheque had bounced and that he now owed them $0.00 and unless
he sent a cheque by return of post them would be taking steps to recover the debt.
Credits:
