Feedback would have saved much more if it had arrived earlier
Feedback is essential for correcting process and requirements mistakes and misunderstandings. Late feedback delays the correction of existing mistakes and permits making of further mistakes based on existing misunderstandings that could have been corrected.
Feedback allows correction of existing mistakes and prevention of future mistakes, and gives confidence in areas where mistakes were not made. Feedback can occur in all areas of process. This can start, for example, when capturing requirements by paraphrasing the requirement and repeating it back to the originator of the requirement. All stages of the process can provide feedback, all stages of the process can benefit from feedback. Are the inputs to the process suitable for the process? Report back to the supplier of the inputs. Are the outputs of the process suitable for the recipients? Elicit feedback and act on it. Feedback can be so valuable that it may be worthwhile making major modifications to the process to gain earlier feedback. Hence IterativeDevelopment has almost universally replaced Waterfall for all but the smallest projects.
One particular form of feedback elicitation is covered by approaches for IncompleteRequirements.
EarlyAndRegularDelivery can provide feedback on the end-to-end process and, of particular use, on quality and understanding of the requirements. Where the process cannot support this approach, an alternative approach to gain early feedback from the customer is to BuildPrototypes. Both of these approaches would benefit if applied alongside EngageQualityAssurance; an approach that aims to get good feedback from the customer as soon as anything is ready to test, and may act as proxy for the customer. Even where early delivery to the customer or QA is not feasible, one should attempt to maximize the opportunities for feedback by IterativeDevelopment and IncrementalIntegration.
All Agile methodologies have built in methods to ensure timely feedback. IterativeDevelopment and usually EarlyAndRegularDelivery are the norm; iteration cycles of two weeks or less are common. Close communication with the customer is encouraged, often to the point of having the CustomerOnSite.