Corrective and Preventive Action in ISO 9001:1994

1. MODULE 9 References Resources In service to our customers. Module 9 page 1

2. ISO 9001:1994 4.14 Corrective and preventive action 4.14.1 General The supplier shall establish and maintain documented procedures for implementing corrective and preventive action. Any corrective or preventive action taken to eliminate the causes of actual or potential nonconformances shall be to a degree appropriate to the magnitude of problems and commensurate with the risks encountered. The supplier shall implement and record any changes to the documented procedures resulting from corrective and preventive action. 4.14.2 Corrective Action The procedures for corrective action shall include: a) the effective handling of customer complaints and reports of product nonconformities; b) investigation of the cause of nonconformities relating to product, process and quality system, and recording the results of the investigation (see 4.16, Quality control records); c) determination of the corrective action needed to eliminate the cause of nonconformities; d) application of controls to ensure that corrective action is taken and that it is effective. 4.14.3 Preventive action The procedures for preventive action shall include: a) the use of appropriate sources of information such as processes and work operations which affect quality, concessions, audit results, quality records, service reports and customer complaints to detect, analyze and eliminate potential causes of nonconformities; b) determination of the steps needed to deal with any problems requiring preventive action; c) initiation of preventive action and application of controls to ensure that it is effective; d) confirmation that relevant information on actions taken is submitted for management review (see 4.1.3). Module 9 PW page 3 rev 3-97

3. When analyzing any process remember to ask The Golden Questions. Does a process exist? Is the process documented? Is the process approved? Is the process adequate? Are the process customer’s key characteristics identified? Are measurements established for process key characteristics? Are people trained to carry out the process? Do people have proper work instructions? Are process inputs correct? Are potential process failure modes identified? Are controls established for potential failure modes? Are feedback loops in place for improvement? Module 9 PW page 4

4. Measurement Components Gauging Electronic test Instruments Machine Components Machine Variability Fixtures Tooling Gauges Computers Software People Components Training Experience Attitude Aptitude Material Components External Suppliers Internal Suppliers Consumables Components Assemblies Method Components Grinding vs. Turning Machine vs. Powder Metallurgy Routing Through Shop Procedures Environment Components Temperature Humidity Analyzing a process for sources of variations will lead to investigating how the different inputs affect the process. The following tables list several of the typical sources of variation found in manufacturing and administrative processes. The RCCA process can be used to determine why these sources have caused a process to go out of control and how to fix them. Typical Sources of Variation: Manufacturing/Technical Processes The RCCA Process as a SPC aid Typical Sources of Variation: Administrative/White Collar Processes Measurement Components Counting Sampling Machine Components Office Equipment Computers Software People Components Training Experience Attitude Aptitude Material Components Forms Suppliers Method Components Procedures Policies Accounting Practices Environment Components Temperature Humidity Noise Level Lighting Module 9 PW page 5

5. RISK DECISION MATRIX This decision matrix is to help evaluate whether a problem should be pursued through the Root Cause Analysis & Corrective Action process. It will also help to decide the extent to which to carry your corrective actions and the amount of resources to be applied to them. It helps focus the business team on the implications and risk identified from the business model. It provides a “scientific” way of determining the “essential few” or most critical problems to be addressed by the Root Cause Analysis & Corrective Action process. Severity Ranking (S)Estimate how severe the effect of the problem or variation will be for the next user or customer. This is the factor that represents the seriousness of variation in the eyes of the next user or customer. Rank Criteria 1 Unreasonable to expect that the minor nature of the failure would cause any noticeable effect on the next operation. Customer will probably not be able to detect variation. 2 Variation causes only a slight customer annoyance. Customer will probably notice only minor problems. 3 Customer is made uncomfortable or is annoyed by the problem. For example, moderate rank would be given to undesirable attributes, such as the need for customer to make revisions or corrections. 4 High degree of customer dissatisfaction due to the nature of the problem, such as an unusable product or service. 5 Problem involves potential safety considerations or loss of customer. Frequency Rating (F) Estimate the likelihood that the problem or variation will occur. Regardless of the risk factor calculated below, this frequency ranking is the best indicator of the preventive capability (robustness) of the process. Corrective actions should be considered to reduce high frequency rankings even when the risk factor is otherwise within acceptable limits. Rank Criteria 1 Remote probability of occurrence. 2 Low probability of occurrence. [Process in statistical control.] 3 Moderate probability of occurrence. Associated with processes that have experienced occasional failures, but not in major proportions. [Process in statistical control but not quite capable.] 4 High probability of occurrence. Generally associated with processes that have often failed. [Process in statistical control but not capable.] 5 Very high probability of occurrence, i.e. defect is almost certain to occur. Module 9 PW page 6

6. Detectability Ranking (D) Estimate the probability of passing a problem or variation on to the next user or customer. Rank Criteria 1 Remote likelihood that the product would be passed on or shipped containing that defect. The defect is a “functionally obvious characteristic” that can readily be detected by a subsequent operation. Detection reliability at least 99.99%. 2 Low likelihood that the product would be passed on or shipped containing the defect. The defect is an “obvious characteristic.” Detection reliability at least 99.8%. 3 Moderate likelihood that the product would be passed on or shipped containing the defect. The defect is an “easily identified characteristic.” Detection reliability at least 98%. 4 High likelihood that the product would be passed on or shipped containing the defect. The defect is a “subtle characteristic.” Detection reliability greater than 90%. 5 Very high likelihood that the product would be passed on or shipped containing the defect. Item is not checked or checkable. Defect is one that affects usefulness of product, is latent and would not appear before shipping. Detection reliability 90% or less. Risk Factor (R) = S2 x F x D = Action level Risk Factor Action Level Reasoning 0 to 24 None Risk is acceptable. Do not have to complete RCCA process. 25 to 28 Minimal Risk is acceptable if cost of preventive corrective action is moderate to high (specific corrective action should be taken if possible). Fix if cost is low. 49 to 96 Moderate Risk is acceptable if cost of corrective action is high or preventive barriers are put in place. Otherwise fix. 97 to 192 High Risk warrants considerable cost expenditure. Look for lower cost alternates if cost is prohibitive. 193 + Very High Risk is totally unacceptable. Fix at any cost. Module 9 PW page 7

7. REFERENCES 1. Emery, D.A., The Complete Manager, McGraw-Hill Book Co., New York, 1970. 2. Hodnett, E., The Art of Problem Solving, Harper & Brothers Co., New York, 1955. 3. Marvin, P., Developing Decisions for Action, Dow Jones-Irwin, Inc., Homewood, Illinois, 1971. 4. Kepner-Tregoe’s Problem Solving and Decision Making, Kepner-Tregoe, 1982. 5. Gano, Dean L., “Root Cause and How to Find It,” Nuclear News, August 1987, pp 39-43. 6. R. J. Nertney, J.D. Cornelison, W. A. Trost, Root Cause Analysis of Performance Indicators, WP-21, System Safety Development Center, EG&G Idaho, Inc, Idaho Falls, ID, 1989. 7. J. R. Buys and J. L. Clark, Events and Casual Factors Charting, SSDC-14, System Safety Development Center, EG&G Idaho, Inc., Idaho Falls, ID, August 1978. 8. W. A. Trost and R. J. Nertney, Barrier Analysis, SSDC-29, System Safety Development Center, EG&G Idaho, Inc., Idaho Falls, ID, July 1985. 9. C. H. Kepner and B. B. Tregoe, The New Rational Manager, Princeton Research Press, Princeton, NJ, 1981. 10. Benner, L. Jr. (1975), “Accident investigations: Multilinear events sequencing methods.” Journal of Safety Research. 7,2. 11. Busch, D. A. and Paradies, M. W. (1986, December). User’s Guide for Reactor Incident Root Cause Coding Tree (Rev. 5) (DPST-87-209). Aiken, SC: E.I. Du Pont de Nemours & Co., Inc., Savannah River laboratory. 12. Paramore, B., Petersen, L.R. and Banks, W. W. (1986, February). How adequate are your procedures? Paper presented at the Reactor Training Coordination Program, Chattanooga, TN. 13. Gary W. Spitzkeit and John A. Neiderman, The Guide to Performing Corrective Action, DE-AC04-76-DP00613, Allied Signal, Kansas City Division, Kansas City, MO October 1992. Module 9 PW page 8