Software Testing provides confidence in the quality of the software. The Defect metrics help in analysing the quality up-to an extent. Lesser the defects, more the quality of the software and therefore less cost. This is the ideal goal every Project Manager hopes from the Software Testing Life Cycle. Defects Prevention Process is an activity aimed to identify the root cause of the defects and preventing them from occurring in the future.
There are various ways through which we can learn from the defects history and can target to reduce the defects count. One of the way is to follow a Defects Prevention Process. It is applicable to all types of defects whether from Static testing or Dynamic testing.
It has four stages,
- Testing Processes/Methodologies The existing Software Processes are applied to the Development Life Cycle.
- Analysis stage involves researching the defects encountered in the earlier phases of software testing or analysis of the historical defects data. Once the relevant information is available, the defects are grouped together into the identified reasons.
- Root Cause Analysis follows the Pareto Principle of 80/20 rule which says 80% of the defects are because of the 20% defects causes. The clustering of defects in the Analysis step above would give us areas (defects categories) to focus to reduce defects. The Fish Bone Diagram can be applied to dig deep to find out the exact reason. The above activity to identify the root cause should be discussed as deeper as possible, to reach to the actual reason of the defect cause/category.
- Continuous Learning is a crucial step to optimising the process regularly. The primary reason identified above would need to be addressed and changes are implemented into the processes. The improved processes are then applied to the future projects.