Bring more reviewers into a review process to collaborate and raise issues.
As a process owner, you can add more reviewers (or lead reviewers) to current or future steps on any deliveable.
If you're a reviewer on a specific deliverable, you can add more reviewers. Similarly, lead reviewers can choose to add reviewers or lead reviewers.
This is handy if a reviewer (or lead reviewer) is unavailable to complete a step and you don't want to terminate the review.
You can add reviewers (or lead reviewers) to multiple steps at once. If you have multiple reviews stuck because someone is away you can quickly add additional reviewers (or lead reviewers) to those steps to allow the review to proceed.