WKIN05598 QA Failure Mode Effects Analysis FMEA by B3x0vy

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 TOYOTA INDUSTRIAL                           QUALITY ASSURANCE                            Number:            1 of 4
EQUIPMENT MFG., INC.                            Design Review                                               Revision:
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 SECTION:                                                         SUBJECT:
                       Level 3 instruction                        Failure Mode & Effects Analysis (FMEA)

PURPOSE:   An FMEA can be described as a systematic group of activities intended to: (a) recognize and evaluate
           the potential failure of a product/process and the effects of that failure, (b) identify actions that could
           eliminate or reduce the chance of the potential failure occurring, and (c) document the entire process.
           It is complimentary to the process of defining what a design or process must do to satisfy the customer.
           All FMEAs focus on the design, whether it be of the product, or process.
RESPONSIBILITY: TIEM performs FMEAs as determined of value by new projects and/or warranty history. Suppliers
                  perform FMEA and submit results to TIEM QE per timing indicated on the TIEM Supplier Quality
                  Project Plan (TSQPP).

1.0 General:
1.1 The purpose of FMEA creation and submission:
1.1.1  Identifies the process functions and requirements,
1.1.2  Identifies potential product and process-related failure modes,
1.1.3  Assesses the effects of the potential failures on the customer,
1.1.4  Identifies the potential manufacturing or assembly process causes and identifies process variables on which
       to focus controls for occurrence reduction or detection of the failure conditions,
1.1.5  Identifies process variables on which to focus process controls,
1.1.6  Develops a ranked list of potential failure modes, thus establishing a priority system for preventive/corrective
       action considerations, and
1.1.7  Documents the results of the manufacturing or assembly process.

2.0 Requirement:
2.1 There are three basic cases for which FMEAs are generated, each with a different scope or focus:
Case 1: New designs, new technology, or new processes. The scope of the FMEA is the complete design,
          technology, or process.
Case 2: Modifications to existing design or process (assumes there is a FMEA for the existing design or process).
          The scope of the FMEA should focus on the modification to the design or process, possible interactions due
          to the modification, and field history.
Case 3: Use of an existing design or process in a new environment, location or application (assumes there is a
          FMEA for the existing design or process). The scope of the FMEA is the impact of the new environment or
          location on the existing design or process.
2.2 A FMEA is used to identify potential problem areas associated with manufacturing and assembling a product.
      Cross-functional teams should study each step of the process for possible failure modes, effects of failures, and
      potential causes. Existing conditions should then be reviewed and rated for the likelihood of occurrence [0],
      severity [S], and detection [D].
2.2.1     The product of these ratings is the risk priority number (RPN) for each possible cause of failure. The RPN's
          establish priorities for investigating countermeasures for each potential cause of failure. As countermeasures
          are implemented, the results are recorded, and RPN's recalculated. Because product and process
          conditions change frequently, the FMEA must always reflect the current manufacturing environment.

3.0    Procedure:
3.1    The FMEA begins by developing a list of what the process is expected to do and what it is expected not to do,
       i.e., the process intent.
3.2    The Process FMEA should begin with a flow chart of the general process. This flow chart should identify the
       product/process characteristics associated with each operation. Identification of some product effects from the

      WRITTEN               CHECKED                    AFFECTED DEPARTMENTS                        APPROVED
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 TOYOTA INDUSTRIAL                          QUALITY ASSURANCE                             Number:            2 of 4
EQUIPMENT MFG., INC.                           Design Review                                                Revision:
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       corresponding Design FMEA, should be included, if available. Copies of the flow chart used in FMEA
       preparation should accompany the FMEA.
3.3    Team is established and is assigned to gather past problem history on similar old model parts.
3.4    An outline of the process flow and equipment to be used for production is created.
3.5    All information gathered is entered onto the FMEA Blank Form either in hardcopy or electronically.
3.6    Each individual, specific process should be listed in the Component and Function column of the FMEA.
3.7    The next column should include all the potential failures that could occur at that process.
3.8    The effects of the potential failures should be listed in the following column.
3.9    The causes for the potential failures should be listed next.
3.10   The current controls for the process should be placed in the next column. These should include: visual
       inspection, checksheets, gages, etc.
3.11   Severity, Occurrence, and Detection rating scales are then added to each item. These are scales ranging 1-10
       from least problematic to the greatest. (See Tables #1, #2 & #3)
3.12   The RPN should then be established by multiplying the 3 ratings together. RPN= Severity X Occurrence X
       Detection. The higher the RPN the more the potential risk for the process to fail.
3.13   The recommended actions to control the potential failure should be listed along with responsibility and when the
       actions are to be completed.
3.14   Finally the actions taken should be listed along with the new RPN to see what effects the recommended actions
       had on the process.
3.15   After all data has been gathered and ratings have been established the team leader will approve the FMEA and
       issue it to all appropriate department representatives.

4.0    Supplier Responsibility:
4.1    The supplier must submit a FMEA (FORM01761, or SAE J-1739, or AIAG Format) per the time indicated on the
       TIEM Supplier Quality Project Plan (TSQPP), using the format provided.
4.2    The supplier may be required to re-submit FMEA's on an ongoing basis when they have been revised to reflect
       pilot production evaluation or have been affected by ECI, specification change, or countermeasures. Re-
       submission is per the timing indicated on the TSQPP or as negotiated between the supplier and TIEM QE.
4.3    Suppliers are encouraged to use the AIAG supplemental manual "Potential Failure Mode and Effects Analysis"
       as a reference for proper methods and procedures for constructing FMEA analyses.
4.4    The supplier will be responsible for informing the TIEM QE of any changes in the FMEA after start-up, whether it
       be process change or due to any countermeasure activity.

5.0 Follow-up:
5.1 The need for taking effective preventive/corrective actions, with appropriate follow-up on those actions, cannot be
    overemphasized. Actions should be communicated to all affected activities. A thoroughly thought-out and well-
    developed FMEA will be of limited value without positive and effective preventive/corrective actions.
    Assessment for corrective actions are aimed to provide continuous improvement. The intent is to reduce the
    potential risk for the process to fail.

       References:
5.2           SAE J-1739
5.3           AIAG supplemental manual “Potential Failure Mode and Effects Analysis”
5.4           FORM01761      “FMEA Format”
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 TOYOTA INDUSTRIAL                     QUALITY ASSURANCE                                   Number:               3 of 4
EQUIPMENT MFG., INC.                      Design Review                                                         Revision:
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                                             Table #1
                                 PFMEA SEVERITY RANKING CRITERIA

                             Criteria: Severity of Effect (Customer or Manufacturing/ Assembly
                Effect                                                                                Ranking
                                                            Effects)
        Hazardous without   Very high severity ranking when a potential failure mode affects
        warning             safe vehicle operation and/or involves noncompliance with
                                                                                                        10
                            government regulation without warning, or may endanger operator
                            (machine or assembly) without warning
        Hazardous with      Very high severity ranking when a potential failure mode affects
        warning             safe vehicle operation and/or involves noncompliance with
                                                                                                        9
                            government regulation with warning, or may endanger operator
                            (machine or assembly) with warning
        Very High           Vehicle/item inoperable (loss of primary function). Vehicle/item
                            repaired in repair department with a repair time greater than one           8
                            hour. 100% of product may have to be scrapped.
        High                Vehicle/item operable but at a reduced level of performance.
                            Vehicle/item repaired in repair department with a repair time
                                                                                                        7
                            between half an hour and an hour. Product may have to be sorted
                            and a portion (less than 100%) scrapped.
        Moderate            Vehicle/item operable but comfort / convenience item(s) inoperable.
                            Vehicle/item repaired in repair department with a repair time less
                                                                                                        6
                            than half an hour. A portion (less than 100%) of the product may
                            have to be scrapped with no sorting.
        Low                 Vehicle/item operable but comfort / convenience item(s) operable at
                            a reduced level of performance. Vehicle/item repaired off-line but
                                                                                                        5
                            does not go to repair department. 100% of product may have to be
                            reworked.
        Very Low            Fit & finish / squeak and rattle item does not conform. Product may
                            have to be sorted, with no scrap and a portion (less than 100%)             4
                            reworked.
        Minor               Portion (less than 100%) of the product may have to be reworked,
                            with no scrap, on-line but out-of-station. Fit & finish / squeak and        3
                            rattle item does not conform.
        Very Minor          Portion (less than 100% of the product may have to be reworked,
                            with no scrap, on-line but in-station. Fit & finish / squeak and rattle     2
                            item does not conform
        None                No Effect                                                                   1




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 TOYOTA INDUSTRIAL                          QUALITY ASSURANCE                                   Number:             4 of 4
EQUIPMENT MFG., INC.                           Design Review                                                       Revision:
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                                                  Table #2
                                     PFMEA DETECTION RANKING CRITERIA

             Detection                       Criteria           Suggested Range of Detection Methods        Ranking
       Almost Impossible            Absolute certainty of       Cannot detect or is not checked
                                                                                                              10
                                    non-detection
       Very Remote                  Controls will probably      Control is achieved with indirect or
                                                                                                              9
                                    not detect                  random checks only
       Remote                       Controls have poor          Control is achieved with visual
                                                                                                              8
                                    chance of detection         inspection
       Very Low                     Controls have poor          Control is achieved with double visual
                                                                                                              7
                                    chance of detection         inspection only
       Low                          Controls may detect         Control is achieved with charting
                                                                                                              6
                                                                methods
       Moderate                     Controls may detect         Control is based on variable gauging
                                                                after parts have left the station, or GO/
                                                                NO GO gauging performed on 100%               5
                                                                of the parts after parts have left the
                                                                station
       Moderately High              Controls have a good        Error detection in subsequent
                                    chance to detect            operations, or gauging performed on
                                                                                                              4
                                                                setup and first-piece check (for set-up
                                                                causes only)
       High                         Controls have a good        Error detection in-station, or error
                                    chance to detect            detection in subsequent operations by
                                                                multiple layers or acceptance: supply,        3
                                                                select, install, verify. Cannot accept
                                                                discrepant part
       Very High                    Controls almost certain     Error detection in-station (automatic
                                    to detect                   gauging with automatic stop feature).         2
                                                                Cannot pass discrepant part
       Very High                    Controls certain to         Discrepant parts cannot be made
                                    detect                      because item has been error-proofed by        1
                                                                process/product design


                                                Table #3
                                   PFMEA OCCURRENCE RANKING CRITERIA

                   Probability of Failure                 Potential Failure Rates               PPM         Ranking
       Very High: Persistent Failures                               > 1 in 2                  500,000         10
                                                                      1 in 3                  333,333         9
6.0    High: Frequent Failures                                        1 in 8                  125,000         8
                                                                     1 in 20                   50,000         7
       Moderate: Occasional Failures                                 1 in 80                   12,500         6
                                                                    1 in 400                    2,500         5
                                                                   1 in 2000                     500          4
       Low: Relatively Few Failures                               1 in 15,000                     67          3
                                                                 1 in 150,000                    6.67         2
       Remote: Failure is Unlikely                             < 1 in 1,500,000                  0.67         1

								
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