Software development fundatmentals

Chapter 4 of "Rapid Development" by Steve McConnell

3. Quality assurance fundamentals

Pay attention to quality assurance fundamentals from day 1.

Facts:

• Most of the delayed software projects are due to the defects;
• The products will lowest defect rate were also the ones with shortest schedules;
• 20% modules occupy 80% defects;
• The longer the defect is not solved, the more it costs;

3.1. Error-prone modules

Identify 20% error prone modules, and fix/redesign them.

3.2. Testing

Testing effectiveness varies enormously. Typically unit test find 10~50% defects, system test has 20~60%, but both of them can only catch less than 60% defects.

Testing typically slows the development speed, but it has to be done. And it has to be done as early as possible. Develop a good test design in the first place is the key to all module and system developments.

3.3. Technical reviews

• Walkthroughs;
• Code reading;
• Inspections;
• Peer review.

3.4. Following the instructions

Especially SOP.