Why Testing is so important

Advantage of Early Defect Detection

Data to support the need for early fixes of software defects is supplied by several reports. The National Institute of Standard Technology (NIST) published a study in 2002 noting that the cost of fixing one bug found in the production stage of software is 15 hours compared to five hours of effort if the same bug were found in the coding stage.

The Systems Sciences Institute at IBM has reported that the cost to fix an error found after product release was four to five times as much as one uncovered during design, and up to 100 times more than one identified in the maintenance phase (Figure 1).

Can software defects be prevented by simply logging them into some “defect tracking tool/system,” documenting them and providing fixes for them? The obvious answer is no, though this is the first step toward defect prevention.

Defect prevention involves a structured problem-solving methodology to identify, analyze and prevent the occurrence of defects. Defect prevention is a framework and ongoing process of collecting the defect data, doing root cause analysis, determining and implementing the corrective actions and sharing the lessons learned to avoid future defects.