What aspect is essential for ensuring the quality of deliverables in SAFe?

Frequent user feedback is crucial for ensuring the quality of deliverables in the SAFe framework. By obtaining regular feedback from users, teams can validate assumptions, understand their needs better, and make necessary adjustments to the product in real time. This iterative process allows for quick identification of issues or areas for improvement, ensuring that the final product aligns with user expectations and requirements. Engaging users throughout the development cycle helps teams prioritize features accurately and fosters a culture of continuous improvement, which is a core tenet of Agile methodologies.

In contrast, while constant code refactoring, comprehensive documentation, and delayed testing phases can have their roles in software development, they do not directly contribute to the quality assurance process as effectively as frequent user feedback does. Constant code refactoring, for instance, focuses more on technical debt and code quality but lacks direct engagement with user needs. Comprehensive documentation can provide context and guidelines but does not replace the need for actual user insights. Delayed testing phases can lead to discovering critical issues too late in the process, which can ultimately affect the deliverables' quality and timeliness. Thus, the emphasis on frequent user feedback aligns with SAFe's principle of customer collaboration over contract negotiation.