Quality Assurance "QA" - an important step AFTER your crawls have been run. From the Wayback machine or from a hosts report, content is checked to determine if links behave as expected. If not, "patch" crawls are run.
Patch crawls: A crawl to capture and patch in documents that were not captured in your original crawl. (Glossary). READ: Modify scope and run patch crawls from your report (below) . Patch crawls don't usually take up much data.
There are a number of ways to run patch crawls, BUT they can only be run on production crawls or saved test crawls.
"Automatic"Quality Assurance - From with the post-crawl hosts report, scoping rules can be edited and patch crawls run.
Manual Quality Assurance - Browse in Wayback to relevant areas of sites & check for relevant files. Missing URLS are logged so that they can be crawled later on in a patch crawl. READ: How to use the Wayback QA Tool (link below).