External Failure and Internal Failure Cost
Definition and Explanation of Quality Costs:
The concept of Cost Of Quality (COQ) has been around for many years. Dr. Joseph M. Juran in 1951 in his Quality Control Handbook included a section on COQ. The Quality Cost Committee under the Quality Management Division was established by the American Society for Quality (ASQ) in 1961. However it was Philip B. Crosby who popularized the use of COQ because of his book Quality is Fre in 1979. Several current quality system standards, ISO 9000, QS-9000, AS-9000, reference the use of COQ for quality improvement.
The concept of Cost of Quality is confusing. It does not refer to costs such as using a higher grade leather to make a wallet or using 14K gold instead of gold plating in jewelry. Instead the term quality cost refers to all of the costs that are incurred to prevent defects or that result from defects in products. What is being referenced are the costs due to the lack of quality or costs to ensure quality is produced. We understand them as the costs that are associated with preventing, detecting, and correcting defective work. Some authors refer to these costs as “Cost of Poor Quality”. Sometimes poor quality costs refer only to the “failure” costs. Crosby refers to the COQ costs as “Price of conformance” (the prevention and appraisal costs) and the “Price of non-conformance” (the failure costs). These are divided into conformance and non-conformance costs, also called control costs and failure of control costs.
Figure 1
Quality costs can be broken down into four broad groups. These four groups are also termed as four (4) types of quality costs. Two of these groups are known as prevention costs and appraisal costs. These are incurred in an effort to keep defective products from falling into the hands of customers. The other two groups of costs are known as internal failure and external failure. Internal and external failure costs are incurred because defects are produced despite efforts to prevent them
The concept of Cost Of Quality (COQ) has been around for many years. Dr. Joseph M. Juran in 1951 in his Quality Control Handbook included a section on COQ. The Quality Cost Committee under the Quality Management Division was established by the American Society for Quality (ASQ) in 1961. However it was Philip B. Crosby who popularized the use of COQ because of his book Quality is Fre in 1979. Several current quality system standards, ISO 9000, QS-9000, AS-9000, reference the use of COQ for quality improvement.
The concept of Cost of Quality is confusing. It does not refer to costs such as using a higher grade leather to make a wallet or using 14K gold instead of gold plating in jewelry. Instead the term quality cost refers to all of the costs that are incurred to prevent defects or that result from defects in products. What is being referenced are the costs due to the lack of quality or costs to ensure quality is produced. We understand them as the costs that are associated with preventing, detecting, and correcting defective work. Some authors refer to these costs as “Cost of Poor Quality”. Sometimes poor quality costs refer only to the “failure” costs. Crosby refers to the COQ costs as “Price of conformance” (the prevention and appraisal costs) and the “Price of non-conformance” (the failure costs). These are divided into conformance and non-conformance costs, also called control costs and failure of control costs.
Figure 1
Quality costs can be broken down into four broad groups. These four groups are also termed as four (4) types of quality costs. Two of these groups are known as prevention costs and appraisal costs. These are incurred in an effort to keep defective products from falling into the hands of customers. The other two groups of costs are known as internal failure and external failure. Internal and external failure costs are incurred because defects are produced despite efforts to prevent them
References: 1. Jones, Capers, Patterns of Software Systems Failure and Success, International Thompsom Computer Press, Boston, Mass., 1996. 2. Crosby, P., Quality Improvement Through Defect Prevention, Philip Crosby Assosiates, 1985. 3. Beecroft, G. Dennis, What is Your Quality Costing You? IIQP Newsletter, Winter 2000. 4. Campanella, Jack (Ed.). Principles of Quality Costs (Third Edition). ASQ Quality Press: Milwaukee, Wisconsin. 1999. 219pp. 5. Harrington, H.J., Poor Quality Costs, Mercel Dekker, Inc., 1987. 6. Morse, Roth, and Poston, Measuring, Planning, and Controlling Quality Costs, National Association of Accountant, 1987.