Advanced pfmea

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Advanced pfmea

  1. 1. Process Failure Mode Effect Analysis CA/PA-RCA : Advanced Tool Northrop Grumman Corporation Integrated Systems
  2. 2. Overview Objective  Failure Mode Effect Analysis (FMEA) – Provide a Basic familiarization with a tool that aids in quantifying severity, occurrences and detection of failures, and guides the creation of corrective action, process improvement and risk mitigation plans. 2
  3. 3. Agenda  FMEA History  What IS FMEA  Definitions  What it Can Do For You  Types of FMEA  Team Members Roles  FMEA Terminology  Getting Started with an FMEA  The Worksheet  FMEA Scoring 3
  4. 4. Agenda 4 Why does it always seem we have plenty of time to fix our problems, but never enough time to prevent the problems by doing it right the first time?
  5. 5. FMEA History This “type” of thinking has been around for hundreds of years. It was first formalized in the aerospace industry during the Apollo program in the 1960’s.  Initial automotive adoption in the 1970’s.  Potential serious & frequent safety issues.  Required by QS-9000 & Advanced Product Quality Planning Process in 1994.  For all automotive suppliers.  Now adopted by many other industries.  Potential serious & frequent safety issues or loyalty issues. 5
  6. 6. What is FMEA ? Cause & effect, Root Cause Analysis, Fishbone Diagram Etc Failure Mode Effect Analysis 6
  7. 7. What is FMEA ? Definition: FMEA is an Engineering “Reliability Tool” That:  Helps define, identify, prioritize, and eliminate known and/or potential failures of the system, design, or manufacturing process before they reach the customer. The goal is to eliminate the Failure Modes and reduce their risks.  Provides structure for a Cross Functional Critique of a design or a Process  Facilitates inter-departmental dialog.  Is a mental discipline “great” engineering teams go through, when critiquing what might go wrong with the product or process.  Is a living document which ultimately helps prevent, and not react to problems. 7
  8. 8. What is FMEA ? What it can do for you! 1.) Identifies Design or process related Failure Modes before they happen. 2.) Determines the Effect & Severity of these failure modes. 3.) Identifies the Causes and probability of Occurrence of the Failure Modes. 4.) Identifies the Controls and their Effectiveness. 5.) Quantifies and prioritizes the Risks associated with the Failure Modes. 6.) Develops & documents Action Plans that will occur to reduce risk. 8
  9. 9. Types of FMEAs ? System/Concept “S/CFMEA”- (Driven by System functions) A system is a organized set of parts or subsystems to accomplish one or more functions. System FMEAs are typically very early, before specific hardware has been determined. Design “DFMEA”- (Driven by part or component functions) A Design / Part is a unit of physical hardware that is considered a single replaceable part with respect to repair. Design FMEAs are typically done later in the development process when specific hardware has been determined. Process “PFMEA”- (Driven by process functions & part characteristics) A Process is a sequence of tasks that is organized to produce a product or provide a service. A Process FMEA can involve fabrication, assembly, transactions or services. 9
  10. 10. Types of FMEAs ? System/Concept “S/CFMEA”- (Driven by System functions) A system is a organized set of parts or subsystems to accomplish one or more functions. System FMEAs are typically very early, before specific hardware has been determined. Design “DFMEA”- (Driven by part or component functions) A Design / Part is a unit of physical hardware that is considered a single replaceable part with respect to repair. Design FMEAs are typically done later in the development process when specific hardware has been determined. Process “PFMEA”- (Driven by process functions & part characteristics) A Process is a sequence of tasks that is organized to produce a product or provide a service. A Process FMEA can involve fabrication, assembly, transactions or services. 10
  11. 11. The FMEA Team Roles Champion / Sponsor Provides resources & support Attends some meetings Promotes team efforts Shares authority / power with team Kicks off team Implements recommendations Team Leader “Watchdog” of the project Good leadership skills Respected & relaxed Leads but doesn’t dominate Maintains full team participation Typically lead engineer FMEA Core Team 4 – 6 Members Expertise in Product / Process Cross functional Honest Communication Active participation Positive attitude Respects other opinions Participates in team decisions Recorder Keeps documentation of teams efforts FMEA chart keeper Coordinates meeting rooms/time Distributes meeting rooms & agendas 11 Facilitator “Watchdog“ of the process Keeps team on track FMEA Process expertise Encourages / develops team dynamics Communicates assertively Ensures everyone participates
  12. 12. FMEA Terminology 1.) Failure Modes: (Specific loss of a function) is a concise description of how a part , system, or manufacturing process may potentially fail to perform its functions. 2.) Failure Mode“Effect”: A description of the consequence or Ramification of a system or part failure. A typical failure mode may have several “effects” depending on which customer you consider. 3.) Severity Rating: (Seriousness of the Effect) Severity is the numerical rating of the impact on customers.  When multiple effects exist for a given failure mode, enter the worst case severity on the worksheet to calculate risk. 4.) Failure Mode“Causes”: A description of the design or process deficiency (global cause or root level cause) that results in the failure mode . You must look at the causes not the symptoms of the failure. Most failure Modes have more than one Cause. 12
  13. 13. FMEA Terminology (continued) 5.) Occurrence Rating: Is an estimate number of frequencies or cumulative number of failures (based on experience) that will occur (in our design concept) for a given cause over the intended “life of the design”. 6.) Failure Mode“Controls”: The mechanisms, methods, tests, procedures, or controls that we have in place to PREVENT the Cause of the Failure Mode or DETECT the Failure Mode or Cause should it occur . Design Controls prevent or detect the Failure Mode prior to engineering release 7.) Detection Rating: A numerical rating of the probability that a given set of controls WILL DISCOVER a specific Cause of Failure Mode to prevent bad parts leaving the facility or getting to the ultimate customer. Assuming that the cause of the failure did occur, assess the capabilities of the controls to find the design flaw.. 13
  14. 14. FMEA Terminology (continued) 8.) Risk Priority Number (RPN): Is the product of Severity, Occurrence, & Detection. Risk= RPN= S x O x D Often the RPN’s are sorted from high to low for consideration in the action planning step (Caution, RPN’s can be misleading- you must look for patterns). 9.) Action Planning: A thoroughly thought out and well developed FMEA With High Risk Patterns that is not followed with corrective actions has little or no value, other than having a chart for an audit Action plans should be taken very seriously. If ignored, you have probably wasted much of your valuable time. Based on the FMEA analysis, strategies to reduce risk are focused on: Reducing the Severity Rating. Reducing the Occurrence Rating. Reducing the detection Rating. 14
  15. 15. Getting Started on FMEA What Must be done before FMEA Begins! Understand your Customer Needs Develop & Evaluate Product/Process Concepts Create an Effective FMEA Team =QFD =Brain Storming =4 to 6 Consensus Based Multi Level Experts = What we Define the FMEA are and are Scope not working Determine1 Product or Process Functions 15 Ready? 2 Determine Failure Modes of Function Determine “Effects” of3 The Failure Mode Develop and Drive 7 Action Plan Severity Rating Determine 4 “Causes” of The Failure Mode Occurrence Rating Determine5 “Controls” Detection Rating 6 6 Calculate & Assess Risk
  16. 16. The FMEA Worksheet Product or Process Failure Mode Failure Effects 1 2 3 Determine Product or Process Functions Determine “Effects” of The Failure Mode Determine Failure Modes of Function Severity Rating S O E Causes C Controls V C 4 5 D R Actions E P / Plans T N 6 p O C C p p D R E P T N 7 Develop and Drive Action Plan Determine “Controls” Determine “Causes” of The Failure Mode Occurrence Rating Resp. & p Target S Complete E Date V Detection Rating Calculate & Assess Risk If an FMEA was created during the Design Phase of the Program, USE IT! Create an Action Plan for YOUR ROOT CAUSE and Re-Evaluate the RPN Accordingly 16
  17. 17. FMEA Scoring Severity None Low Moderate High Extreme Severity of Effect 17 Rating May endanger machine or operator. Hazardous without warning 10 May endanger machine or operator. Hazardous with warning 9 Major disruption to production line. Loss of primary function, 100% scrap. Possible jig lock and Major loss of Takt Time Reduced primary function performance. Product requires repair or Major Variance. Noticeable loss of Takt Time Medium disruption of production. Possible scrap. Noticeable loss of takt time. Loss of secondary function performance. Requires repair or Minor Variance Minor disruption to production. Product must be repaired. Reduced secondary function performance. Minor defect, product repaired or "Use-As-Is" disposition. Fit & Finish item. Minor defect, may be reprocessed on-line. 8 7 6 5 4 3 Minor Nonconformance, may be reprocessed on-line. 2 No effect 1
  18. 18. FMEA Scoring Occurrence Very High Likelihood of Occurrence Failure Capability Rate (Cpk) Rating High Moderate Process is not in statistical control. Similar processes have experienced problems. Process is in statistical control but with isolated failures. Previous processes have experienced occasional failures or out-of-control conditions. Remote Low Process is in statistical control. 18 < .33 10 1 in 3 > .33 9 1 in 8 > .51 8 1 in 20 > .67 7 1 in 80 > .83 6 1 in 400 > 1.00 5 1 in 2000 Failure is almost inevitable 1 in 2 > 1.17 4 1 in 15k > 1.33 3 > 1.50 2 > 1.67 1 Process is in statistical control. Only isolated failures associated with almost identical processes. 1 in 150k Failure is unlikely. No known failures associated with almost identical processes. 1 in 1.5M
  19. 19. FMEA Scoring Detection Very Low No known control(s) available to detect failure mode. Low Likelihood that control will detect failure Controls have a remote chance of detecting the failure. Rating 10 9 Moderate 8 7 Controls may detect the existence of a failure 6 Very High High 5 19 Controls have a good chance of detecting the existence of a failure The process automatically detects failure. Controls will almost certainly detect the existence of a failure. 4 3 2 1
  20. 20. FMEA Scoring RPN or Risk Priority Number The Calculation ! Severity x Occurrence x Detection= RPN 20
  21. 21. Failure Modes & Effect Analysis (FMEA) Part or Process Improvement  FMEA is a technique utilized to define, identify, and eliminate known or potential failures or errors from a product or a process.  Identify each candidate Part or Process, list likely failure mode, causes, and current controls  Prioritize risk by using a ranking scale for severity, occurrence, and detection  Mitigate risk – Can controls be added to reduce risk? Recalculate RPN.  Characteristics with high Risk Priority Numbers should be selected for Improvement and Action Plans Created  Recalculate RPN After Completion of Action Plans to Validate Improvements Hole Drilling 21 Failure Mode Failure Effects S O E Causes C Controls V C Oversize Unable to Hole Install BP 5 Fastener Wrong Drill Bit Used 8 Ball Gage Visual Insp D R E P T N Actions / Plans Resp. & Target Complete Date 120 Product or Process Kit Drill Bits 010103 3 p S E V p O C C p p D R E P T N 51 1 5
  22. 22. Failure Modes & Effect Analysis Questions? Call or e-mail: Kevin M. Treanor 310-863-4182 kevin.treanor@ngc.com 22 Bob Ollerton 310-332-1972/310-350-9121 robert.ollerton@ngc.com

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