The distinction between the two is simply that CoQ in a cost accounting system includes all costs attributable to quality. Salaries, overhead, and preventive costs are included. In Cost of Poor Quality, only the costs directly relating to failure need be considered. Scrap, rework, added inspection, and things of that nature are calculated. There are a number of good discussions in the Cove on the subject as well as some nice sample worksheets. Do a search to see if there is anything you can use.