Besides loading and validating submissions, VALIDATE is used to reject submissions for technical reasons. If VALIDATE reports a high error, your submission could be rejected. This rejection could take up to five days to be reported. When an original or supplement is rejected, your PDUFA time clock will not start.
Some divisions in the FDA have what is called an integrity reviewer. The integrity reviewer uses the VALIDATE report with REVIEW to ensure the submission is reviewable. This reviewer checks for many deficiencies, including but not limited to, broken hyperlinks, missing content, and STF files that are provided.
Other divisions do not have an integrity reviewer. In those cases, it is up to each reviewer to ensure the submission is sound. If they find the submission is suspect, they inform groups like the Office of Business Informatics to do some more investigation.
Across centers and divisions at the FDA, reviewers generally spend the most time in Sequence View. The primary use of Sequence View is reviewing the most recent information provided by sponsors. While more time is spent in Sequence View, the other views are readily used by reviewers as well. Many reviewers live in the Lifecycle View because it allows them to understand the application as a whole. For example, when looking at a study, certain reviewers want to understand how the protocol changed over time. Typically, managers will work in the Current View. These reviewers want to understand the current state of the application.
Currently the Regulatory Activity View is used more by CBER than CDER. This is because CBER has integrated GlobalSubmit REVIEW with their tracking system and do not rely on the eCTD submission to organize their Regulatory Activity. I would suspect CDER will start using the Regulatory Activity View more once they integrate their submission tracking system with GlobalSubmit REVIEW.
As you can see, there is not one way the FDA uses GlobalSubmit REVIEW and VALIDATE.