All component software objects built in the construction phase should be tested in isolation, ensuring that expected behavior occurs from "good" and "bad" input.

After unit testing of all software objects, it is time to perform full scale tests that include:

• Integration - tests that all software works in concert and produces expected results from a cradle-to-grave perspective)
• System - tests that the technical architecture performs in the expected manner in terms of response, recovery, back-up, error-correction, loading and stress
• Acceptance - ensures that users see the results they expect
• Security
• Application software distribution