Testing
Testing of software (or a system) is needed to make sure it works properly.

Complete testing of non-trivial programs using all possible situations is not usually possible. Enough tests are carried out until there is a high degree of confidence that the program works correctly.

 

Unfinished software may first undergo an alpha test within the developers. Then a beta test of a complete program may be carried out by invited people (magazine reviewers etc) in exchange for constructive feedback.
A test plan is a scheme for testing a program (or system) giving details of the tests and the data that is to be used.

The data used for testing must include..

  • normal values
  • extreme values (very large, very small etc)
  • invalid data (silly data!)
  • null data

 

If a test fails to produce the expected results, corrections need to be made and the whole series of tests will need to be repeated.

 

Fixing one error may cause another to appear!
Exercise : Testing
Software needs to be tested to make sure that . Whole new computer systems also need to be tested.

A test plan is devised giving details of and the data that is to be used.

The test data must include normal data, null data, invalid data and data. 

 

(Green indicates success)