Here's a little hint on creating a view that will display items or document that hasn't been updated for a specific period of time.
Create a new view of your list or document library.
Give it a descriptive name and select the fields you want to display
If you got files in folders, select to 'Show all item without folders' under Folders, Folders or Flat
Under Filter select the options that form the criteria for the documents or items you want to look at. In the question about the date, you could use the built in Modified column or use one of your own custom columns, like I do below.
The trick is to use the built-in [Today] feature and the subtract to number of days you want to test for. So, in this case, I looking for documents that has the SKU Test Result set to 'Pass', but has a SKU Test Date that is more than 330 days old. Remember, no spaces in [Today]-330.
The resulting view shows all the documents that needs to be re-tested soon and the responsible person can take the needed actions.