index > 2.1.1 Fundamentals of computer systems


Reliability is improved by doing thorough testing. Testing is done to find problems so they can be fixed which improves the computer system.

Testing can never be complete because:

There are too many things to test in a complex system.

For good testing, you must test:

Example: A program which checks if an input is between 1 and 10.
Normal data - 5.
Erroneous data - 11 or ABC.
Extreme data - 1 or 10.