3. 'External failure costs' is one of the four 'costs of quality'. (4) a) Give an example of a company that has had very high 'external failure costs' recently. b) State the other three 'costs of quality'. Costs of Quality (COQ) Appraisal costs Costs of the inspection, testing, and other tasks to ensure that the product or process is acceptable . Prevention costs . Sum of all the costs to prevent defects Internal failure costs Costs for defects incurred within the system: scrap, rework, repair