Overview of Testing - Software Testing: Testing Across the Entire Software Development Life Cycle - page 27

Although Y2K testing did represent a very specifi c kind of defect detection and
correction, a surprising number of more general testing techniques were appropri-
ate for retesting the remediated (Y2K-corrected) programs. Thus, the Y2K testing
frenzy directed a spotlight on the larger issues, processes, and strategies for full
development life cycle software testing. These principles are an amalgam of the
professional testing experience from the 1980s and 1990s and the Y2K experience to
yield the following underlying software testing principles.

Principles of good testing

1.
2.
3.
4.
5.
6.

Business risk can be reduced by fi nding defects.
Positive and negative testing contribute to risk reduction.
Static and execution testing contribute to risk reduction.
Automated test tools can substantially contribute to risk reduction.
Make the highest risks the fi rst testing priority.
Make the most frequent business activities (the 80/20 rule) the second
testing priority.
Statistical analyses of defect arrival patterns and other defect charac-
teristics are a very effective way to forecast testing completion.
Test the system the way customers will use it.
Assume that defects are the result of process and not personality.
Testing for defects is an investment as well as a cost.

7.

8.
9.
10.

KEY TERMS

Test l i m it s
Test i ng obje ct ives
Multiple testing
approaches

Test i ng complet ion
Ver i f ier
Requirements
Development risk

Risk assessment
Return on investment
(ROI)
80/20 rule

KEY CONCEPTS

• Testing is a technical profession with a signifi cantly different mindset, and

with signifi cantly different concepts and skills from those of the technical
developer profession.
All engineering projects introduce defects into the new system or product.
Making a business decision not to fi nd the defects, by not testing, will not
make them go away.

•