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FMEA

ME 190ME CODES, LAWS and ETHICS

failure modes and effects analysis1

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objectivesTo understand the use of Failure Modes Effect Analysis (FMEA)To learn the steps to developing FMEAsTo summarize the different types of FMEAsTo learn how to link the FMEA to other Black Belt toolsTo perform an exercise to actually perform an FMEA2

whats with fmea?Allows us to identify areas of our process that most impact our customersHelps us identify how our process is most likely to failPoints to process failures that are most difficult to detect3

application example

Manufacturing: A manager is responsible for moving a manufacturing operation to a new facility. He wants to be sure the move goes as smoothly as possible and that there are no surprises.Design: A design engineer wants to think of all the possible ways a product he is designing could fail so that he can build robustness into the product.4

failure modeThe way in which the component, subassembly, product, input, or process could fail to perform its intended functionFailure modes may be the result of upstream operations or may cause downstream operations to failThings that could go wrongfailure mode and effect analysisis a methodology to evaluate failure modes and their effects in designs and in processes. 5

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why use fmea?Methodology that facilitates process improvementIdentifies and eliminates concerns early in the development of a process or designImprove internal and external customer satisfactionFocuses on preventionFMEA may be a customer requirementFMEA may be required by an applicable Quality System Standard7

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why use fmea?Methodology that facilitates process improvementIdentifies and eliminates concerns early in the development of a process or designImprove internal and external customer satisfactionFocuses on preventionFMEA may be a customer requirementFMEA may be required by an applicable Quality System Standard8

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using fmeaTeam identifies potential failure modes for design functions or process requirementsThey assign severity to the effect of this failure modeThey assign frequency of occurrence to the potential cause of failure and likelihood of detectionTeam calculates a Risk Priority Number by multiplying severity times frequency of occurrence times likelihood of detectionTeam uses ranking to focus process improvement efforts9

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Fmea form10

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failure mode and effect analysisA structured approach to:Identifying the ways in which a product or process can failEstimating risk associated with specific causesPrioritizing the actions that should be taken to reduce riskEvaluating design validation plan (product) or current control plan (process)11

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when to conduct?Early in the process improvement investigationWhen new systems, products, and processes are being designedWhen existing designs or processes are being changedWhen carry-over designs are used in new applicationsAfter system, product, or process functions are defined, but before specific hardware is selected or released to manufacturing12

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historyFirst used in the 1960s in the Aerospace industry during the Apollo missionsIn 1974, the Navy developed MIL-STD-1629 regarding the use of FMEAIn the late 1970s, the automotive industry was driven by liability costs to use FMEALater, the automotive industry saw the advantages of using this tool to reduce risks related to poor quality13

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Fmea form

Identify failure modes and their effectsIdentify causes of the failure modesand controlsPrioritizeDetermine and assess actions

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types of fmeaDesignAnalyzes product design before release to production, with a focus on product functionAnalyzes systems and subsystems in early concept and design stages

ProcessUsed to analyze manufacturing and assembly processes15

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types of fmea

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a team toolA team approach is necessary.Team should be led by the Black Belt, a responsible manufacturing engineer or technical person, or other similar individual familiar with FMEA.The following should be considered for team members: Design Engineers Operators Process Engineers Reliability Materials Suppliers Suppliers Customers

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procedure1.For each process input (start with high value inputs), determine the ways in which the input can go wrong (failure mode)2.For each failure mode, determine effectsSelect a severity level for each effect3.Identify potential causes of each failure modeSelect an occurrence level for each cause4.List current controls for each causeSelect a detection level for each cause18

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procedure5.Calculate the Risk Priority Number (RPN)6.Develop recommended actions, assign responsible persons, and take actionsGive priority to high RPNsMUST look at severities rated a 107.Assign the predicted severity, occurrence, and detection levels and compare RPNs19

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inputs and outputs

FMEA

BrainstormingC&E MatrixProcess MapProcess HistoryProceduresKnowledgeExperience

List of actions to prevent causes or detect failure modes

History of actions takenInputsOutputs20

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severity, occurrence and detectionSeverityImportance of the effect on customer requirementsOften cant do anything about thisOccurrenceFrequency with which a given cause occurs and creates failure modesDetectionThe ability of the current control scheme to detect or prevent a given cause21

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rating scalesThere are a wide variety of scoring anchors, both quantitative or qualitativeTwo types of scales are 1-5 or 1-10The 1-5 scale makes it easier for the teams to decide on scoresThe 1-10 scale allows for better precision in estimates and a wide variation in scores (most common)Severity1 = Not Severe, 10 = Very SevereOccurrence1 = Not Likely, 10 = Very LikelyDetection1 = Likely to Detect, 10 = Not Likely to Detect

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risk priority numberRPN is the product of the severity, occurrence, and detection scores.SeverityOccurrenceDetectionRPNXX=23

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exampleWe will conduct an FMEA on the truck stop example we used to create a C&E MatrixA Black Belt wants to improve customer satisfaction with the coffee served at the truck stopThe process map and completed C&E matrix follow

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process mapInputsOutputsInputsOutputsHot WaterSoapScrubberClean CarafeCold WaterMeasuring MarkFull CarafeFilterMaker w/FilterFresh CoffeeDosing ScoopMaker w/Filter & CoffeeBrewing CoffeeCleaned CarafeDirty WaterWet ScrubberFull CarafeFilled MakerEmpty CarafeMaker w/FilterMaker w/Filter & CoffeeOperating MakerHeatBrewed CoffeeHot CoffeeCustomerOrderSize SpecificationComplete OrderHot CoffeeCupFilled CupCustomerCreamSugarAmount DesiredComplete OrderMoneyCoffee DeliveryComplete OrderFilled CupCustomer ReplyAmount SpecifiedComplete OrderMake ChangeTemperatureTasteStrengthSmileHappy Customer

Pour Coffee into CupOffer Cream & SugarComplete TransactionSay Thank YouReceive Coffee OrderClean CarafeFill Carafe w/WaterPour Water into MakerPlace Filter in MakerPut Coffee in FilterSelect Temperature SettingTurn Maker On25

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c&e matrix

We will focus on one of the two steps with the highest scores26

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step 1: determine potential failure modes27

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step 2: identify effects and assign severity28

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step 3: identify potential causes29

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step 4: list current controls for each cause and assign score30

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step 5: calculate RPN31

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step 6: develop recommended actions, assign persons and take actions32

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step 7: assign the Predicted Severity, Occurrence, and Detection Levels and Compare RPNs33

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