Fmea Presentation 2

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How to create an organization and implement FMEA on shop-floor

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Fmea Presentation 2

  1. 1. Subikash Roy –Director Process Operations – Asia Pacific Schaeffler Holding (China) Co. Ltd.
  2. 2. Using FMEA Intelligently – Techniques to Review PFMEA on Shopfloor Page 1
  3. 3. Objectives, Purpose and Scope of a PFMEAPurpose • To predict failure modes • To analyze effects of failures • To build in safety and quality into the process • To continuously improve robustness of processesScope • Ultimate user • External customer • Internal customer • Society and EnvironmentMeasurement • Severity • Occurrence • Detection • RPN • Customer & Supplier Rejections • High Inprocess RejectionsTarget • Zero Defects • Safety and Quality to customersDeployment Process • Deployment of shopfloor data to adjust Occurrence and DetectionFramework • Review mechanisms and methods for PFMEA updating•Focus • Prediction of variations in shopfloor process Using FMEA Intelligently – Techniques to Review PFMEA on Shopfloor Page 2
  4. 4. Inputs to Process FMEA Process Flow Diagram  Analyze flow of Process  Team knowledge of manufacturing/ assembly process required  Identify the incoming sources of variation  Identify the desired outcomes  What is the process supposed to do?  What is its purpose  What is its function? Using FMEA Intelligently – Techniques to Review PFMEA on Shopfloor Page 3
  5. 5. PFMEA Special Characteristics PFMEA SPECIAL CHARACTERISTICS TABLE FMEA Type Classification To Indicate Criteria Actions Required Product Effect Assembly Effect Customer/ Process  Critical Characteristic Severity = 9, 10 Special Control Required* Process SC Significant Severity = 5-8, Special Control Characteristic Occurrence = 4-10 Required* Manufacturing/ Process HI High Impact Severity = 4-7 Emphasis** Characteristic Occurrence = 4-10 Process OS Operator Safety Severity = 9, 10 Safety Sign-off Process  Special requirements As required by Customer As required by Customer* Included in Control Plan** Included in Q-Alerts, Special WI etc. Using FMEA Intelligently – Techniques to Review PFMEA on Shopfloor Page 4
  6. 6. Process Function Requirements In Process FMEAs, functions have the following 2 components:  Process characteristics or process requirements. These include operating conditions and process parameters like job rates and production maintenance requirements.  Product specification requirements for the operations including the item dimensions and all associated engineering requirements (i.e., engineering spec., performance spec.)– Example: Operation #20: Drill hole size X mm, through depth Y mm Using FMEA Intelligently – Techniques to Review PFMEA on Shopfloor Page 5
  7. 7. How to Identify Potential Failure Modes? Type of Failure Categories of How to Identify Failure Mode What to Check Mode Failure Mode• Why would the item be rejected at System Appropriate & Valid Std. No Functionthis process operation?• How would the item not conform to Partialspecification at this process Manufacturing Dimension, Surface Finish Functionoperation? Relational, Part• What would the next operator or Over Function Assembly Missing, Misaligned, Disorisubsequent operators consider entedunacceptable? Time Degraded Receiving Receiving Inspection• What would the ultimate customer Function Inspectionfind unacceptable?• Is there a possibility to fail Unintended Testing/ Testing/ Inspectionregulatory compliance? Function Inspection Using FMEA Intelligently – Techniques to Review PFMEA on Shopfloor Page 6
  8. 8. Causes and Effects of FailuresUsing FMEA Intelligently – Techniques to Review PFMEA on Shopfloor Page 7
  9. 9. Severity Ratings – Changed only through change in product or process design Criteria: Severity of Effect This ranking results when a potential failure mode results in a final customer and/or a Effect manufacturing/assembly plant defect. The final customer should always be considered first. If Ranking both occur, use the higher of the two severities. Criteria: Severity of Effect Defined Hazardous Or may endanger operator (machine or assembly) without warning. High Accidents on 10without warning machine/ operator.Hazardous with Or may endanger operator (machine or assembly) with warning. 9 warning Or 100% of product may have to be scrapped, or vehicle/item repaired in repair department Very High 8 with a repair time greater than one hour. Or product may have to be sorted and a portion (less than 100%) scrapped, or vehicle/item High 7 repaired in repair department with a repair time between a half-hour and an hour. Or a portion (less than 100%) of the product may have to be scrapped with no sorting, or Moderate 6 vehicle/item repaired in repair department with a repair time less than a half-hour. Or 100% of product may have to be reworked, or vehicle/item repaired off-line but does not go Low 5 to repair department. Very Low Or the product may have to be sorted, with no scrap, and a portion (less than 100%) reworked. 4 Or a portion (less than 100%) of the product may have to be reworked, with no scrap, on-line Minor 3 but out-of-station. Or a portion (less than 100%) of the product may have to be reworked, with no scrap, on-line Very Minor 2 but in-station. None Or slight inconvenience to operation or operator, or no effect. 1 Using FMEA Intelligently – Techniques to Review PFMEA on Shopfloor Page 8
  10. 10. Process Controls Points to consider  To increase probability of Detection, process and/ or design revisions are required.  Generally, improving Detection controls is costly & ineffective for quality improvements.  Increasing quality control or inspection frequency is not a positive corrective action and should be utilized only as a temporary measure.  In some cases, a design change to a specific part may be required to assist in Detection.  Changes to current control system may be implemented to increase probability of Detection.  Emphasis must be on preventing defects (i.e., reducing Occurrence) Using FMEA Intelligently – Techniques to Review PFMEA on Shopfloor Page 9
  11. 11. Using FMEA Intelligently – Techniques to Review PFMEA on Shopfloor Page 10
  12. 12. Triggering the PFMEA Man Machine Material Method Measurement Management • Skill Change • Low MTBF, High • Not conform to • Process Change • Faulty measurement •Takt Time change • New Operator MTTR spec. • Six Sigma Projects equipment (Self & supplier) • Non-std. activities • Not trained • High Rejections • Supplier process • Value Stream • Infrequent calibration • Not conform no. Senior & Middle Management sufficiently after • High quality variation change •High & recurring in-process of jobs per hour method change variation • Inconsistent tool • Kaizen project rejections • Cycle time higher • Operating new • New machine wear • Bypass Poka Yoke/ • High supplier rejections than planned machine • New product on • New substituted Safety • High & recurring customer • FMEA Review STRATEGY • New product in machine material • Supplier Method complaints System CHECK production change • Tool capability low • Supplier change OCCURRENCE RATING ADJUST • In-process Rejections Trend - <If continuously increasing for >1 week> • Customer complaints Trend - <If continuously increasing for > 1 week> ACT DETECTION RATING ADJUST • High frequency of problem being detected outside process (Detection Probability = Pieces detected outside process/ Total pieces produced) <Includes Internal & External Customers>Lower Mgmt. & Operator. • No. of customer complaints related to FMEA Failure Modes EXECUTION • Sort out Issues by Priority (5s of Mind and Action) • Prepare timing plan for each issue PLAN • Monitoring system including coaching and mentoring of employees where required • Recurrence and Sustenance criteria • Verify actual Data from Shopfloor Check • Observe in Gemba for issues (include Mura and Muri also) DO • Use appropriate QC tools for arriving at Root Cause of the problem Do Act • Check and verify solution for recurrence and sustenance • Check for convenience of operation to operator Plan • Communication solution to Higher Management Using FMEA Intelligently – Techniques to Review PFMEA on Shopfloor Page 11
  13. 13. Occurrence Ratings From Actual Process Performance Possible FailureProbability of Failure Cpk Ranking Rates 1 in 2 < 0.33 10Very High: Failure is almost inevitable 1 in 3 ≥ 0.33 9High: Generally associated with processes similar to 1 in 8 ≥ 0.51 8previous processes that have often failed 1 in 20 ≥ 0.67 7Moderate: Generally associated with processes 1 in 80 ≥ 0.83 6similar to previous processes which have 1 in 400 ≥ 1.00 5experienced occasional failures, but not in majorproportions 1 in 2,000 ≥ 1.17 4Low: Isolated failures associated with similar 1 in 15,000 ≥ 1.33 3processesVery Low: Only isolated failures associated with 1 in 150,000 ≥ 1.5 2almost identical processesRemote: Failure is unlikely. No failures ever 1 in 1,500,000 ≥ 1.67 1associated with almost identical processesAbove Figures are only indicative samples Using FMEA Intelligently – Techniques to Review PFMEA on Shopfloor Page 12
  14. 14. Detection Ratings from Actual Process Performance Criteria: Likelihood the existence of a defect will be Detection detected before product advances to next or subsequent Ranking process or to customer Almost Detection Probability < 80 % 10 Impossible Very Remote Detection Probability 80 % 9 Remote Detection Probability 82.5 % of failures 8 Very Low Detection Probability 85 % of failures 7 Low Detection Probability 87.5 % of failures 6 Moderate Detection Probability 90 % of failures 5Moderately High Detection Probability 92.5 % of failures 4 High Detection Probability 95 % of failures 3 Very High Detection Probability 97.5 % of failures 2 Almost Certain Detection Probability 99.5 % of failures 1Above Figures are only indicative samples Using FMEA Intelligently – Techniques to Review PFMEA on Shopfloor Page 13
  15. 15. Suggested Detection Methods based on Ranking Detection Criteria Suggested Range of Detecting Methods Ranking Error Proof Inspection Gauging Manual Almost Absolute certainty of non- Cannot detect or is not checked 10 Impossible detectionImprove Process Very Remote Controls will probably not Control is achieved by indirect or random checks only 9 Robustness detect Remote Controls have very poor Control is achieved with visual inspection only 8 chance of detection Very Low Controls have poor chance Control is achieved with double visual inspection only 7 of detection Low Controls may detect Control is achieved by SPC 6 Moderate Control may detect Control is based on variable post process gauging. OR Go/NoGo 5 gauging performed on 100% of parts post process. Moderately Controls have a good Error detection in subsequent operations OR gauging performed 4 High chance to detect in setup and first piece check. High Controls have a very good Error detection in-process OR in subsequent process by multiple 3 chance to detect layers of acceptance. Cannot pass discrepant part. Very High Controls almost certain to Error detection in-process by automatic gauging with stop 2 detect feature. Cannot accept discrepant part. Extremely Controls certain to detect Discrepant parts cannot be made because item has been error 1 High proofed by DFMEA Using FMEA Intelligently – Techniques to Review PFMEA on Shopfloor Page 14
  16. 16. Re-rating RPN After Actions Have Occurred– Severity typically stays the same. This can only be changed through product/ process redesign– Occurrence is the primary item to reduce / focus on.– Detection is reduced only as a last resort.– DO NOT PLAN TO REDUCE RPN WITH DETECTION ACTIONS!!!  100% inspection is only 80% effective!  Reducing RPN with detection does not eliminate failure mode, or reduce probability of causes  Detection of 10 is not bad if occurrence is 1 Using FMEA Intelligently – Techniques to Review PFMEA on Shopfloor Page 15

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