Failure Mode and Effect Analysis (DFMEA / PFMEA) Presentation

Transcription

1 Failure Mode and Effect Analysis (DFMEA / PFMEA) Presentation ASQ Miami, FL September 18th, 2018

2 ASQ Presentation Agenda What is FMEA? FMEA History Design & Process development Design (DFMEA)& Process (PFMEA) links FMEA & Quality Standard links What is DFMEA? DFMEA Inputs 10 steps to conduct a DFMEA DFMEA Worksheet Techniques for customizing the Severity, Occurrence, and Detection Ranking What is PFMEA? PFMEA Inputs 10 Steps to Conduct a PFMEA Use of the FMEA Analysis Worksheet. Techniques for customizing the Severity, Occurrence, and Detection Ranking Scales for a PFMEA 2

3 FMEA Presentation The purpose of this presentations is three-fold: (a) Neophytes: Develop theoretical framework of the FMEA methodology. (b) Practitioners: Refresher of the tool set and environment for a successful FMEA deployment. (c) Practicum Some examples. 3

4 FMEA Glossary AIAG FMEA - Automotive Industry Action Group, 4 th Edition Published June 2008 B-diagram Block diagram DFMEA Diagram Failure Modes and Effects Analysis Failure mode - the way in which something (product or service) might fail Effects analysis studying the consequences of the various failure modes to determine their severity to the customer. PFD - Process Flow Diagram PFMEA - Process Failure Modes and Effects Analysis PCP - Process Control Plan P-diagram Parameter diagram RPN Risk Priority Number SAE FMEA J Society of Automotive Engineers, published March

5 Introduction to Failure Mode & Effects Analysis - FMEA

6 What is FMEA? A systemized group of activities designed to: Recognize and evaluate the potential failures of a product/ service/ process and its effects in the customer eyes (perception is reality) Prioritize the risk of such failures, using a Risk Priority Number (RPN) Identify corrective actions geared to eliminate or reduce the chance of a potential failure Prioritize the corrective actions Document and carry out such corrective actions, using SMART Document the process(es) 6

7 History of FMEA 1949 U.S. Navy Bureau of Aeronautics, & Bureau of Naval Weapons (MIL-P-1649, Procedures for Performing a Failure Mode, Effects and Criticality Analysis) 1963 NASA (APOLLO Project) 1965 Aerospace Industry (FMECA) 1970s Department of Defense (MIL-STD-1629A) 1975 Nuclear Industry 1977 Ford Motor Company (Pinto) 1980 DIN VDA Volume 4 (Verband der Automobilindustrie) 1992 Ford, Chrysler & GM 2008 Automotive Industry Action Group (AIAG) It is accepted as an engineering reliability tool 7

8 FMEA Terms What is a Failure Mode? Failure modes are the ways in which a product or a process can fail. Incorrect behavior of a subsystem or component due to a physical or procedural malfunction. Identify defects or errors, potential or actual, in a product design or process, with emphasis on those affecting the customer or end user. The way in which the component, subassembly, product, input, or process could fail to perform its intended function. Failure modes may be the result of upstream operations or may cause downstream operations to fail. Things that could go wrong! 8

9 FMEA Terms What is Effects Analysis? A failure effect is the result of a failure mode on the product or system function as perceived by the customer or end-user. Effects are the ways that these failures can lead to waste, defects or harmful outcomes for the customer. Incorrect behavior of the system caused by a failure. Effects are classified based on internal and external customers (e.g. another downstream processes and final clients). The study of consequences of identified failures is called effects analysis. 9

10 FMEA Terms What is Criticality Analysis? Criticality is the combined impact of the probability that a failure will occur and the severity of its effect Criticality analysis can be used for more than just ranking each potential failure. By identifying the characteristics that make each operation or task critical, the analysis will also provide valuable information to decide what actions will reduce risk for all operations is a process. Criticality analysis is an important tool that provides information for decisions about corrective actions priority, justifying resources to conduct process improvements, and developing reliability strategies. 10

11 Why perform an FMEA? Preventing problems is cheaper and easier than cleaning them up (Prevention less expensive than Detection) Some things are too risky or costly to incur mistakes. Example is the space shuttle where we are putting human lives in a tin can and sending them to space and getting them home safely. Mitigate risks of Failure in both Design and Process, by managing the bathtub curve Help identify and prioritize risks for customers, the business, our personnel, the environment, etc. 11

12 Why perform an FMEA? Managing the bathtub curve Wikipedia (2018). Bathtub Curve, Retrieved from It describes a particular form of the hazard function which comprises three parts: an infant mortality period with a decreasing failure rate followed by a normal life period (also known as "useful life") with a low, relatively constant failure rate and concluding with a wear-out period that exhibits an increasing failure rate. 12

13 When to perform an FMEA? Naik, S. (2015) Risk management using FMEA in pharma. Retrieved from 13

14 Triggers to FMEA FMEA should be conducted or update At the conceptual (system) stage When changes are made to the design When changes are made to the process When new regulations are instituted When customer feedback indicates a problem 14

15 Reasons for an FMEA Get it right the first time (CFMEA, DFMEA) Indentifies any inadequacies in the development of the product (DFMEA) Tests and trials may be limited to a few products (DFMEA) Regulatory reasons (DFMEA) Continuous improvement (PFMEA) Preventive approach (DFMEA, PFMEA) Team building (DFMEA, PFMEA) Required procedures (PFMEA) Cost reduction and increased profits (PFMEA) Demand for higher quality (DFMEA, PFMEA) Retention of knowledge and traceability (all FMEA) 15

16 FMEA Potential Benefits FMEA provides the potential benefits Reduce the likelihood of customer complaints Reduce product development time (time to market) Reduce maintenance and warranty costs Minimize exposure to product failures Reduce the possibility of extended life or reliability failures Reduce the likelihood of product liability claims Aids in improving designs for products and process Contributes to cost savings, improving bottom line results Add to customer satisfaction and loyalty Instill a continuous improvement culture 16

17 Resources Needed This is a real team effort with air cover Commitment of top management to support and sustain deployment and on-going. Knowledgeable individuals Design and Development Engineers Process & Quality Engineers Manufacturing Supervisors and Operators Quality Assurance Individuals attentive to FMEA timelines and deliverables. People resources may be internal or external to the business or a combination. 17

18 Where does FMEA fit? DMAIC Tools Define Measure Analyze Improve Control Statement of Opportunity & Problem Statement Project Scope Team Formation SIPOC Critical To Quality (CTQ) (Affinity diagrams, tree diagram) Quality Function Deployment (QFD) DPMO and sigma level Cost Benefit Analysis Control Charts (SPC initial) Project Plan Gate Review As is Process Maps (traditional swim lanes and Value Stream) Measurement system: Gage R&R Pareto Charts & Graphical Summary (histograms, line charts, SPC charts) Descriptive Statistics for process Process Capability (Cp, Cpk) Data Collection Plan DPMO, Process Yield, sigma level Cost Benefit Analysis (refine) Gate Review Brainstorming tools (Ishikawa, Affinity diagrams, Tree diagrams, Activity network diagrams) Control Charts (SPC refine) Failure Mode and Effect Analysis (FMEA) QFD (review) Prevention versus Detection Data Collection Plan (expanded) Hypothesis Testing & ANOVA Design of Experiments DPMO, Process Yield, sigma level Gate Review FMEA and RPN ranking and corrective actions Hypothesis Testing & ANOVA Brainstorming solutions Potential Solutions: Force Field Analysis, Nominal group techniques, Pugh matrix Poka-Yoke (mistake proofing) To Be process maps Pilot implementation Implementation communication plan Gate Review Statistical Process Control (XmR, Xbar&R, Xbar&s, u, c, np, p) Communication Plan Leverage activities Celebrate 18

19 Where does FMEA fit? The Advanced Product Quality Planning (APQP) methodology consists of four phases and five major activities along with ongoing feedback assessments and corrective actions. APQP process consists of the following outputs by phases. Retrieved from: 19

20 FMEA Limitations (*) Employee training requirements Detailed process requiring focus, time and commitment from the FMEA team Initial impact on product and manufacturing schedules Financial impact required to upgrade design, manufacturing, and process equipment and tools (*)These limitations should be recognized and treated as short term and minimal interruptions to a business. 20

21 Types of FMEA FMEA-FMECA (2006) FMEA/FMECA Types. Retrieved from 21

22 Concept FMEA (CFMEA) CONCEPT Failure Modes and Effects Analysis Used to analyze concepts in the early stages before hardware, software, prototyping, pilots or a manufacturing process are defined (most often during system and subsystems development) Focuses on potential failure modes associated with the proposed functions of a concept proposal or engineering proposal. Includes the interactions of multiple systems and interaction between the elements of a system at the concept stages. 22

23 Design FMEA (DFMEA) Design Failure Modes and Effects Analysis Focus is on potential product design-related failures and their causes. Look at design requirements (drawings, product specifications, P-diagrams) to identify components and their relations with other components. Assists in the objective evaluation of design requirements and design alternatives. Aids in the initial design for manufacturing and assembly. Increases the probability that potential failure modes are considered and mitigated. Provides additional information to aid in the planning of efficient design testing. 23

24 Process FMEA (PFMEA) Process Failures Modes and Effects Analysis Focuses is on potential process failures and their causes (customer line of sight) Recommended corrective actions are targeted at eliminating the root cause of the potential failures Identify potential product related process steps failure modes Assess the potential customer effects (impact) of these failures Identify the potential manufacturing causes to focus on Develop a ranked list of potential failure modes 24

25 Design Failure Mode & Effects Analysis (DFMEA)

26 DFMEA/PFMEA Interrelationships Boundary Diagram, P-Diagram, etc. Customer / Product Requirements Process Flow Diagram (PFD) Design FMEA (DFMEA) Process FMEA (PFMEA) Design Verification Plan & Report (DVP&R) Process Control Plan (PCP), SPC, Mistake Proofing 26

27 DFMEA Team Requirements Team composition Team Leader / Facilitator Design and Development Engineers Process Engineers Manufacturing Supervisors and Operators Others Participate as needed Quality Assurance Quality Engineers Customers of product Suppliers of raw materials and equipment. 27

28 DFMEA - Inputs B-diagram, P-diagram Examples Retrieved from: 28

29 DFMEA - Inputs Product Definition & Design Requirements Design requirement document (if available from customer) Legal and technical regulations Compliance documentation Drawings, sketches, animations, and simulations Description of systems and components What are the functions of the components listed on the BOM? 29 Design Matrix Bill of Materials (BOM) Part characteristics List of hardware components quantities Product characteristics & specifications Process constraints equipment, plant layout, space Components and/or samples as supplied by the customer Conditions for use - Identify significant constraints in the conditions involved when the Customer uses of the product.

30 DFMEA - Inputs List Customer Expectations Appearance Looks Good; clean; shiny; no defects... Performance Resistant to damage; starts and runs... Processability Easy to use & easy to make... Environmental green product, eco-friendly Effects or Consequences How can the product/service fail? What could be the result of failure mode? Identify Effects as perceived by Customer. Describe in terms of what the customer might experience or notice. Customer dissatisfaction Warranty costs and production line rework Consider customer to also be internal customers as well as final or ultimate end users. 30

31 DFMEA Function & Failure Modes 31

32 DFMEA - Inputs Previous Experience (Lessons Learned from others) Experience with similar concepts, designs, and DFMEA Customer and supplier inputs Design guides and design standards (for example ASME codes). 32

33 DFMEA Template Retrieved from: 33

34 DFMEA - Methodology 1. Complete the top of the form 2. List items and functions 3. Document potential failure modes 4. Document the potential effects of failure 5. Rate the severity of the failure effect 6. Document potential causes and mechanisms of failure 7. List any critical or special characteristics 8. Detection rate 9. Calculate the RPN of each potential failure effect RPN = (Severity) x (Occurrence) x (Detection) 10. Define recommended actions 11. Assign action items 12. Complete Action Results Section of DFMEA 13. Repeat: undertake the next revision of the DFMEA 34

35 DFMEA Severity, Occurrence & Detection Criteria Score Rank Comments / Criteria 1 None No Effect. 2 Very Minor 3 Minor Fit/Finnish Do Not Conform. Defect Noticed By Discriminating Customer. Performance Nominal Fit/Finnish Do Not Conform. Defect Noticed By Average Customer. Performance Nominal. 1 Remote Failure Is Unlikely <1 in 1,000,000 4 Very Low Fit/Finnish Do Not Conform. Defect Noticed By Most 2 Customers. Performance Nominal. Very Low Relatively Few Failures 1 in 150,000 3 Device Operable, But Convenience Options Operate At Low Not Uncommon 1 in 15,000 5 Low Reduced Performance Levels. Customer Experiences 4 Some Moderate Occasional Failures 1 in 2,000 Score Dissatisfaction. Rank Comments / Criteria Moderate Device Operable, But Convenience Options Inoperable. 5 Frequent Failures 1 in Moderate Almost Design controls will almost certainly detect a potential Highcause/ 1 Certain Customer Experiences mechanism Some and Dissatisfaction. subsequent failure mode. 6 Likely Very Frequent Failures 1 in 100 Device Operable, But At Reduced Performance Levels. 7 High Very high chance the design control will detect a potential cause/ 2 Very Customer High Dissatisfied. mechanism and subsequent failure mode. 7 High Failure Is Typical 1 in 25 8 Very High Device Inoperable High chance With Loss the Of design Primary controls Function. will detect 8 a potential Very High cause/ Repeated Failures 1 in 19 3 High mechanism and subsequent failure mode. Hazardous A Potential Failure Mode Makes Operation Unsafe 9To Severe Failure Is Almost Inevitable 1 in 5 9 (With Moderately Operator And/or Moderately Involves high Non-Compliance chance the design With controls will detect a potential Warning) 4 High Government Regulations cause/ mechanism With Warning. and subsequent 10 failure mode. Extreme Failure Is Normal > 1 in 2 10 Severity Hazardous A Potential Failure Moderate chance Makes Operation the design Unsafe controls To will detect a potential cause/ (Without 5 Moderate Operator And/or mechanism Involves Non-Compliance and subsequent failure with Government mode. Warning Regulations With Warning. Low chance the design controls will detect a potential cause/ 6 Low mechanism and subsequent failure mode. Score Rank Comments / Criteria Failure Rate Occurrence 7 Very Low 8 Remote Very low chance the design controls will detect a potential cause/ mechanism and subsequent failure mode. Remote chance the design controls will detect a potential cause/ mechanism and subsequent failure mode Very Remote 10 Absolute Uncertainty Very remote chance the design controls will detect a potential cause/ mechanism and subsequent failure mode. No Control. Design control will not and/or can not detect a potential cause/ mechanism and subsequent failure mode. Detectability

36 DFMEA - Outputs Design Improvement Plan Identify Design Controls Recommended Action(s) Responsibility & Target Dates Actions Taken Complete Risk Analysis Design Controls Designed Experiments (DOE) Customer Validation Tests, Trial Runs Test Protocols, test Methods Subcontractor or third-party testing Engineering General Practice Ranges 36

37 DFMEA - Benefits Assists during the design phase in reducing risks. Evaluates design requirements / alternatives. Identifies how a product may fail to meet its intended function. Examines potential consequences of failure. Prioritizes corrective actions needed. 37

38 Process Failure Mode & Effects Analysis (PFMEA)

39 Process FMEA Used to identify potential process failure modes by ranking failures and establishing priorities for corrective actions, and its impact on internal and/ or external customers. Focus is on potential process related failures and their causes. Main drive is to understand the process through the identification of as many potential failures as possible. Example: Incorrect material used Development of recommended corrective actions is targeted at eliminating the root cause of the potential failures. PFMEA typically assumes that the design is sound. Otherwise, DFMEA 39

40 Process FMEA Process FMEA (PFMEA) discovers failures that impacts product quality, reduced reliability of the process, customer dissatisfaction, and safety or environmental hazards derived from: Human Factors Methods followed while processing Materials used Machines utilized Measurement systems impact on acceptance Environment Factors on process performance 40

41 Process FMEA Three Parts Process Flow Diagram (PFD) Process Failure Mode and Effects Analysis (PFMEA) Process Control Plan (PCP) 41

42 PFMEA Information Flow Customer Requirements: SOR, Product / Service Tech Specs, System Technical Specs Product Definition: Key Product Characteristics, DFMEA Process Definition: Process Flow Diagram (PFD), Product & Process Characteristics Failure Mode Analysis: PFMEA Control Strategy: Control Plan, SPC, Error proofing Manufacturing: Work Instructions, SPC, Process Monitoring 42

43 DFMEA/PFMEA Interrelationships Boundary Diagram, P-Diagram, etc. Process Flow Diagram (PFD) Design FMEA (DFMEA) Process FMEA (PFMEA) Design Verification Plan & Report (DVP&R) Process Control Plan (PCP), SPC, Mistake Proofing 43

44 Process FMEA - Inputs (Updated) Process maps (swim lanes, VSMs, flow charts) Brainstorming results Ishikawa diagrams Process history and logs Process knowledge 44

45 PFMEA - Process Flow Diagrams The Process Flow Diagram (PDF) provides a logical (visual) depiction of the process that is being analyzed. Most common: Swim lanes maps Value stream maps (VSMs) Flow diagrams Start Process Step Data Input Decision Point Process Step Document End 45

46 Steps to Conduct a PFMEA 1. Review the process Use a Process Flowchart Diagram (PFD) to identify each process component 2. Brainstorm potential failure modes Review existing documentation and data for clues (Ishikawa diagram) 3. List potential effects of failure There may be more than one for each failure 4. Assign Severity rankings Based on the severity of the consequences of failure 5. Assign Occurrence rankings Based on how frequently the cause of the failure is likely to occur 6. Assign Detection rankings Based on the chances the failure will be detected prior to the customer finding it 7. Calculate the RPN Severity * Occurrence * Detection 8. Develop the action plan Define who will do what by when 9. Take action Implement the improvements identified by your PFMEA team 10. Calculate the resulting RPN Re-evaluate each of the potential failures once improvements have been made and determine the impact of the improvements 46

47 PFD Feeds PFMEA Process map steps Munk, J. (2013). Six Sigma Failure Modes and Effects Analysis. Six Sigma Daily. Retrieved from: 47

48 PFMEA Risk Assessment Factor 48

49 PFD Feeds PFMEA 49

50 PFMEA Risk Identification Function: Process Step Effects Severity (1-10) Failure Mode Controls Detectability (1-10) Causes Occurrence (1-10) RPN = Risk * Priority * Number RPN = S * O * D = 1 to 1,000 50

51 PFMEA RPN Guidelines Munk, J. (2013). Six Sigma Failure Modes and Effects Analysis. Six Sigma Daily. Retrieved from: 51

52 FMEA Criticality Matrices Elneil, T. (2-015). Risk Assessment for CAPA Determination, Retrieved from 52

53 PFMEA Process Control Plan (PCP) PCP will be based on the previous activities in PFD and PFMEA. Review the PFMEA information developed & supplied and use to identify: Specific controls that may be needed due to the information added Identify which controls are Product or Process Note any special characteristics Identify evaluation methods, frequency and control methods Note Reaction Plans (particularly related to NC parts) 53

54 PFMEA Process Control Plan (PCP) 54

55 Published Guidelines J1739, SAE for the automotive industry. AIAG FMEA-3, Automotive Industry Action Group. ARP5580, SAE for non-automotive applications. EIA/JEP131, provides guidelines for the electronics industry, from the JEDEC/EIA. P , provides guidelines for NASA s GSFC spacecraft and instruments. SEMATECH A-ENG, provides guidelines for semiconductor equipment industry. 55

56 References Lean Six Sigma - FMEA, isixsigma.com, McDerrmot, Mikulak, and Beauregard, The Basics of FMEA, Productivity Inc., MIL-STD-1629A, Procedures for Performing a Failure Mode, Effects and Criticality Analysis, Nov MIL-STD-882B, O Conner, Practical Reliability Engineering, 3rd edition, Revised, John Wiley & Sons, Chichester, England, QS9000 FMEA reference manual (SAE J 1739). Sittsamer, Risk Based Error-Proofing, The Luminous Group, Stunell Technology

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