Innovative Approach to FMEA Facilitation

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Based on March 2009 Quality Progress article- FMEA Minus the headache

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Innovative Approach to FMEA Facilitation

  1. 1. Innovative Approach to FMEA facilitation Govind Ramu, P.Eng, ASQ CQMgr, CQE, CSSBB, CQA, CSQE, CRE, ASQ Fellow, QMS 2000 Principal Auditor IRCA (UK) Past Section Chair Ottawa Valley- ASQ Canada http://www.asq.org/sixsigma/about/govind.html
  2. 2. History of the FMEA •• The FMEA discipline was developed in the United States The FMEA discipline was developed in the United States Military in 1949 (Military Procedure MIL-P-1629, titled Military in 1949 (Military Procedure MIL-P-1629, titled Procedures for Performing a Failure Mode, Effects and Procedures for Performing a Failure Mode, Effects and Criticality Analysis. Criticality Analysis. •• The first formal application of FMEA discipline was used in The first formal application of FMEA discipline was used in aerospace in mid 60s. aerospace in mid 60s. •• It was used as a reliability evaluation technique to determine It was used as a reliability evaluation technique to determine the effect of system and equipment failures. Failures were the effect of system and equipment failures. Failures were classified according to their impact on mission success and classified according to their impact on mission success and personnel/equipment safety. personnel/equipment safety. •• Reference: SAE JJ1739 and AIAG. Reference: SAE 1739 and AIAG.
  3. 3. What is FMEA? A structured approach to A structured approach to Identify the way in which a design // process can fail to meet Identify the way in which a design process can fail to meet critical customer requirements. critical customer requirements. Estimating the risk of specific causes with regard to the failures. Estimating the risk of specific causes with regard to the failures. Evaluating the Current control plan for preventing the failures from Evaluating the Current control plan for preventing the failures from occurring. occurring. Prioritizing the actions that should be taken to improve the design/ Prioritizing the actions that should be taken to improve the design/ process. process.
  4. 4. When to use FMEA? FMEA is very beneficial to conduct while designing a product or FMEA is very beneficial to conduct while designing a product or process. process. Design FMEA should be done during initial design of the product. Design FMEA should be done during initial design of the product. Process FMEA should be done during design of manufacturing Process FMEA should be done during design of manufacturing process. process. Process FMEA can be performed for legacy products and processes Process FMEA can be performed for legacy products and processes also ififthe process carry high risks to product quality, customer, safety, also the process carry high risks to product quality, customer, safety, etc. etc.
  5. 5. Different Types of FMEA Design FMEA Process FMEA An analytical technique used An analytical technique used primarily by design responsible primarily by manufacturing engineer/Team to assure responsible engineer/Team to potential failure modes; causes assure potential failure modes; and effects have been causes and effects have been addressed for design related addressed for process related characteristics. characteristics. System, Subsystem, Component level FMEA are possible scopes
  6. 6. Definitions Criticality The Criticality rating is the Severity mathematical product of the Severity and Severity is an assessment of how serious the Occurrence ratings. Effect of the potential Failure Mode is on the Criticality = (S) X (O). This Customer. number is used to place Critical Characteristics priority on items that require additional quality Critical Characteristics are Special planning. Characteristics defined by organization that affect customer Occurrence safety and/or could result in non- compliance with government Occurrence is an assessment of the likelihood regulations and thus require special that a particular Cause will happen and result controls to ensure 100% compliance. in the Failure Mode during the intended life and use of the product. Risk Priority Number Detection The Risk Priority Number is a Detection is an assessment of the likelihood mathematical product of the that the Current Controls (design and process) numerical Severity, Occurrence, will detect the Cause of the Failure Mode or the and Detection ratings. Failure Mode itself, thus preventing it from RPN = (S) X (O) X (D). This reaching the Customer. number is used to place priority on items than require additional quality planning.
  7. 7. Definitions Current Controls FMEA Element Current Controls (design and process) are the mechanisms that prevent the Cause of the FMEA elements are identified or Function analyzed in the FMEA process. Failure Mode from occurring, or which detect the failure before it reaches the Customer. Common examples are Functions, A Function could be any Failure Modes, Causes, Effects, intended purpose of a Controls, and Actions. FMEA product or process. FMEA elements appear as column functions are best headings in the output form. described in verb-noun format with engineering specifications. Failure Mode Cause Effect Failure Modes are sometimes described as A Cause is the means by An Effect is an adverse consequence that the categories of failure. A potential Failure Mode which a particular element Customer might experience. The Customer describes the way in which a product or of the design or process could be the next operation, subsequent process could fail to perform its desired results in a Failure Mode. operations, or the end user. function (design intent or performance requirements) as described by the needs, wants, and expectations of the internal and external Customers. Customer Customers are internal and external departments, people, and processes that will be adversely affected by product failure.
  8. 8. FMEA- A team based effort. • Input is required from shop floor-supervision through to management. • Engineering/ R & D • Service. • Reliability. • Purchasing. • Quality Engineering. • Supplier Quality Engineering • Manufacturing • EH & S, ROHS
  9. 9. FMEA Traditional approach Review design and process using a functional block diagram, system design, architecture and process flow chart. Use a brainstorming approach to gather potential failure modes. Use historical data from customer returns, complaints and internal issues from comparable products or processes. List potential effects, both internal and external, of failure. Assign severity, occurrence and detection (SOD) rankings based on the effect, probability of occurrence of the root cause and ability to detect the root cause before the failure mode happens. Calculate the risk priority number (RPN) by multiplying severity, occurrence and detection rankings. Also, calculate criticality by multiplying severity and occurrence. Prioritize the failure modes (risks) based on RPN score and/or criticality. Take actions to eliminate or reduce the risks.
  10. 10. TRADITIONAL APPROACH FMEA FMEA FMEA FMEA DEVELOPMENT DEVELOPMENT TEAM TEAM PROCESS PROCESS Flow FMEA FMEA chart Forms Forms FMEA FMEA Process Process Prepared Prepared Owner Owner Part No. Part No. Due Date Due Date # # I.D. I.D. By By FMEA FMEA Core Core Process Process Pot Failure Pot Failure Failure Failure Severity Severity DATE DATE Team Team Function Function Mode Mode Effects Effects Pot Pot Current Current Class Class Occurrence Occurrence Detection Detection Causes Causes Control Control
  11. 11. Major issues • Quality of the FMEA • Quantity of Completion • Fundamental issues- Bundling of causes! • Fill it, Shut it, Forget it*! * Courtesy: Famous 80s advertisement campaign from Hero Honda Motor cycle manufacturers India. (On fuel economy)
  12. 12. Pitfalls During development: Not understanding the fundamentals of failure mode effects analysis (FMEA) development. Inadequate representation in the team from subject matter experts. Failing to identify the right inputs for the FMEA. Poor planning before assembling for brainstorming and failure ranking. During implementation: Breaking the sessions into weekly meetings (thus losing continuity). Using severity, occurrence and detection (SOD) scales that are not representative of the industry, product family or process group. Failing to learn from the risks exposed at the component and module- level FMEA while drafting at the system level FMEA. Allowing the rigor of the tool to drive the intensity of initial interactions, causing fatigue for participants.
  13. 13. Pitfalls (Continued) During implementation: (Continued) Wasting time on risk-rating debates. Failing to follow through on recommended actions. Failing to drive actions across the board in a systemic way. Failing to integrate the learning from design and process FMEAs or to link to control plans, critical to quality characteristics and critical to process parameters. During sustainability: Not incorporating the identified, mitigated risks into manufacturing guidelines to be used for future product development. Failure to keep the FMEA alive by including feedback from subsequent stages of the product life cycle.
  14. 14. Sources of data Customer Returns- DPPM data % Defective, Defects per Unit Product Design related BODY OF KNOWLEDGE E.g. Performance, reliability, etc. Process Control Similar sources of data from comparable E.g. Out of Spec, Contamination Process Design related Products, processes of Organization Supplier caused E.g. Opportunity for error E.g. Out of Spec, non conformance, etc. Process Control E.g. Out of Spec, Contamination Customer caused DFMEA / PFMEA E.g. damage, S/W error, etc. (Potential) Supplier caused Failure mode-Effects-Causes E.g. Out of Spec, non conformance, etc. Customer Complaints External Knowledge Customer complaints on Known Industry failure product or system performance -Technical journals, publications, With No product return or RMA -Conferences, etc. Internal Ongoing Reliability issues Supplier feedback Periodic Surveillance E.g. Out of Spec Product/Process Design Related E.g. tight unrealistic tolerances, Capability. Product or Process Changes E.g. failure, etc. Process control issues E.g. traceability, yield, etc.
  15. 15. Scope Process (Process FMEA) • Formulate Cross functional Team • Understand Customer/Process Requirements. • Define the start and end of the Process • All team members to walk and observe the process. • Get the assemblers/ process operators to explain the process. • Team makes notes and observations.
  16. 16. Brainstorm all potential causes for the failure modes Inputs: INNOVATIVE APPROACH Process Flow charts, Manufacturing WI, Historical process defect pareto, lessons learned, Etc
  17. 17. Brainstorming Software feature Microsoft VISIO®
  18. 18. Brainstorm all potential local & end effects for the failure modes
  19. 19. Brainstorm all potential failure modes • Utilize process flow chart-break down each step. • Use knowledge of previous and existing parts/processes. • Review all quality information E.g.: Scrap, rework, RMA,etc. • Talk to internal and external customers. Failure Mode Effect Failure Modes are sometimes described as An Effect is an adverse consequence that the categories of failure. A potential Failure Mode Customer might experience. The Customer describes the way in which a product or could be the next operation, subsequent process could fail to perform its desired operations, or the end user. function (design intent or performance requirements) as described by the needs, wants, and expectations of the internal and Example: external Customers. Does not fit, Cannot load or fasten, poor performance, intermittent failure erratic Example: operation. Fiber Damage, Contamination, hairline crack, Dimension oversize.
  20. 20. Identify potential effects of failure For each failure mode, identify the effect(s) on the current or next process or customer downstream in manufacturing/assembly process. Describe the effects of failure in terms of what the customer might notice or experience.
  21. 21. Cause and Effect Cascade with an example Cause = Corrosion Design Cause Effect = High Resistance Effect Environmental Cause = High Resistance Exposure Effect = Insufficient Current Cause Moisture Cause Cause = Insufficient Current Effect Effect Effect = Dim Bulb Corrosion Cause = Design Cause Effect = Env. Exposure Poor Contact (High Cause Cause = Env. Exposure Effect Resistance) Effect Effect = Moisture Insufficient Cause Current Cause = Moisture Effect Effect = Corrosion Dim Bulb Courtesy: Elsmar Cove
  22. 22. Determine severity rating Severity is an assessment of the seriousness of the effect of Potential failure mode to the customer. Severity applies to effect only. Note: Assigning severity rating should be performed as a team Including customer representative and or Design FMEA engineer. If the customer affected by a failure mode is a user outside the plant, team Should consult them and assign the rating.
  23. 23. Identify all potential causes of failure How the failure could occur? Describe in terms of factors That can be corrected or controlled. There could be more than one cause for each failure!! Example:Improper torque, Inaccurate gauging, inadequate lubrication, etc. Note: Experiments may have to be conducted to determine causes using technical Problem solving. Management should have control on the cause identified. The cause should be at the root level.
  24. 24. Determine occurrence rating Occurrence is how frequently the specific failure cause Mechanism is projected to occur. Define Current Controls Systematic methods/devices in place to prevent or detect Failure modes or causes (before the effect happens). Example: Poke-Yoke, automated control for setup verification Note: If available from a similar process, statistical data should be used to determine Occurrence ranking.
  25. 25. Determine detection ranking Detection is an assessment of the probability that the current process control will detect a Potential cause. Also assess the ability of the process control to detect Low frequency failure modes or prevent from going Into the next process. Note: Random quality checks are unlikely to detect the existence of an isolated Defect and should not influence the detection ranking. Sampling done on a Statistical basis is a valid detection control.
  26. 26. Current Controls Design and Process controls are grouped according to their purpose. Type (1) These controls prevent the Cause or Failure Mode from occurring, or reduce their rate of occurrence. Type (2) These controls detect the Cause of the Failure Mode and lead to corrective action. Type (3) These Controls detect the Failure Mode before the product reaches the customer. The customer could be the next operation, subsequent operations, or the end user. The distinction between controls that prevent failure (Type 1) and controls that detect failure (Types 2 and 3) is important. Type 1 controls reduce the likelihood that a Cause or Failure Mode will occur, and therefore affect Occurrence ratings. Type 2 and Type 3 Controls detect Causes and Failure Modes respectively, and therefore affect Detection ratings.
  27. 27. Calculate the Risk Priority Numbers The Risk Priority Number is the product of Severity (S) X Occurrence (O) X Detection (D) rankings. This value should be used to rank order the concerns In the process using Pareto. The RPN will be between 1and 1000. Criticality is severity multiplied by occurrence. This is also an important metric. RPN can be reduced by improving the detection, but the process issue may remain intact. Criticality can be reduced only by improving the capability or redesign.
  28. 28. Prioritize Corrective actions •Concentrate on the Highest RPN •Do not lose sight on effects with high severity. •Think of how the occurrence can be reduced? •How the detection can be improved? •Where applicable use Mistake proofing techniques. •Introduce changes in a controlled manner.
  29. 29. Reassess rankings when action completed • FMEA must be a Live document. • Review Regularly. • Reassess rankings whenever changes made to product/process. • Add any new defects or potential problems when found.
  30. 30. References • Potential Failure Mode & Effects Analysis, fourth edition, Automotive Industry Action Group, 2008. • Govindarajan “Govind” Ramu, “Metrics That Trigger Actionable Discussions: Prioritize Process Improvements Using Gauge R&R and SPC Capability,” ASQ Six Sigma Forum. • Traditionally, NGT is used to collect ideas: www.asq.org/learn-about-quality/idea-creation- tools/overview/nominal-group.html In FMEA development, it can be used to collect scores of SOD. • Elsmar Cove archived file references. Bibliography Quality Training Portal, Resource Engineering Inc., “What You Need to Know About Failure Mode and Effects Analysis (FMEA),” www.qualitytrainingportal.com/resources/fmea/index.htm. May 2009 QP – Standards Outlook – Dan Reid- Major Upgrade.

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