Many Agile projects are intangible where software is being created, design etc where the requirements are based on an explanation by the stakeholders. It is very easy for the stakeholder not to clarify what they expect and the team misinterprets the requirements, this is also known as the gulf of evaluation. With Agile projects verification and validation is built into the process as it is one of the core strengths of the Agile methodology.
The idea of releasing quickly and frequently works so well because it gives the stakeholders an opportunity to validate and verify the results are as expect so any issues can resolve early in the process. Agile uses regular testing, checkpoints, and reviews to address problems before they get bigger which is called frequent verification and validation. The figure on the right demonstrates the various cycles of verification and validation in XP
This article is part of the our 100 Agile Tools & Techniques epic article based off the PMI list of recommended techniques and tools in their PMI-ACP certification syllabus.