Cost of Quality pg 52 book,”Preventative – satisfying customer requirement completely, accurately
and without defects.Appraisal – expended to examine a product or process and make certain the requirements are being met.Failure – opposite or prevention cost and are the result of the project not operating according to plan. Internal failure is the cost incurred to correct an identified error/defect before customer receives the product. External failure is the cost related to errors/defects not detected and corrected before reaching the customer.”