The main steps are as follows:
A Document Controller (DC) triggers a review cycle by uploading the document.
The DC defines the document Author (the party who prepared it) and the document Reviewer. Both Author and Reviewer can add other co-authors and co-reviewers to assist them in the process.
The Reviewer starts placing comments on the document (similarly to how these are done on PDFs through the various PDF apps). However, these comments are automatically introduced in a Comment Review Sheet (CRS) table which is updated live.
The Reviewer (in collaboration with their co-Reviewers, if any) conclude the set of comments and send the whole package back to the Author for their consideration. The Author can provide their responses either on the automatically produced CRS or directly on the PDF doc mark up. The CRS is automatically updated accordingly. When finished, the Author (in collaboration with their co-Authors, if any) have the option to upload a new document revision (as a result of the Reviewer comments). Then, the CRS, PDF doc mark ups and new PDF doc revision are all sent back to the Reviewer for further consideration
The Reviewer has then the option to approve the document and conclude on the review cycle or respond to the comments if not having received satisfactory feedback. The Reviewer also has the option to raise new comments if necessary, e.g. on the new revision if unsatisfactory.
The process is repeated in as many iterations as possible until the document becomes approved by the Reviewer. The history of comments (CRS + PDF doc mark up + PDF doc revision) are all stored together reflecting the entire review and approval workflow.