Avoid using defect tracking systems during the iteration. Fix bugs discovered in the work underway for the iteration immediately. If it takes a lot of work, create a task in the Spring backlog. However, there is usually no need to log this bug in the defect tracking system. Logging it would only create another work queue and more delay – a waste.
On the other hand, defects found outside the iteration – by an “undone” unit or the final users – are normally tracked in a defect-tracking system.
Try zero tolerance on open defects. Why do people insist on creating defects? They spend effort to insert a defect, then they need to search for it, prioritize it, and finally fix it. Not creating the bug in the first place would be a lot less work.
We do believe it is possible to write bug-free code. We do not believe it is easy or common. Still, focus on preventing defects.
Source: Practices for Scaling Lean & Agile Development – Large, Multisite, and Offshore Product Development with Large-Scale Scrum, Craig Larman and Bas Vodde, Addison Wesley