Poor quality interfe s with this learning cycle. Both lean and agile methods recommend that quality be built into the process, rather than inspected for after-the-fact.
Whenever a problem in quality is found, root cause analysis is conducted to get you to the source of the problem, not only to fix it, but to make sure that it never happens again. Processes and standards are constantly changing and evolving based on the insight gained through discovering quality problems, performing root cause analysis on those problems, and implementing countermeasures to ensure that those quality problems do not happen again.