FailureModeandEffectAnalysis(FMEA)-EasternIllinois失效模式與影響分析（FMEA）-伊利諾斯東部

Failure Mode & Effect AnalysisTom Hannan & Kevin KowalisEastern Illinois UniversitySchool of TechnologyTotal Quality SystemsINT 5133(FMEA) What is FMEA?“Is an analytical technique that combines the technology and experience of people in identifying foreseeable failure modes of a product or process and planning for its elimination.” () Before-The-Event action that makes it easier to find flaws in the systemO R ReliabilityIs the probability of the product to perform as expected for a certain period of time, under the given operating conditions, and at a given set of product performance characteristics. Reliability RequirementsBased on the definition of the part, assembly, or process under consideration, the reliability of each sub-system and the factors involved in the reliability must be found, and the appropriate relationships for each part, class, or module of the product must be computed. Failure RatePeriods of failure can conveniently be modeled by an exponential distribution, and the probability of survival of the product or process may be viewed as:Rt = e (-T *F) = e -(T/o)Rt = the period of operation without failureT = time specified for operation w/o failureF = Failure rateO = the mean time to failure Intent of FMEA An Essential Part of Total Quality Management is FMEA! Provides Training Tracks the progress of a project Helps communicating similar problems Uncovers oversights, misjudgments, and errors Calculate the probabilities of failuresDetermine if product or process failure effects on other aspects. FMEA TeamFMEA methodology is a team effort where the responsible engineer involves who? Assembly Manufacturing Materials Quality Service Supplier Custom er FMEA Documentation Block Diagram Design or Process Intent The Customer Needs and Wants The FMEA Form Class Assignment !Divide up into four groups (N,S,E and W) Change Tire Flashlight Unicycle BicycleMake A Simple Block Diagram Stages of FMEA Quantifying Risk Correcting High Risk Causes Specifying Possibilities Re-evaluation of Risk Specifying Possibilitiesn Functionsn Possible Failure Modesn Root Causesn Effectsn Detection/Prevention Quantifying Riskn Probability of Causen Severity of Effectn Effectiveness of Control to Prevent Causen Risk Priority Number Correcting High Risk Causesn Prioritizing Workn Detailing Actionn Assigning Action Responsibilityn Check Points on Completion Re-evaluation of RiskRecalculation of Risk Priority NumberRPN = (S) * (O) * (D)S = SEVERITYO = OCCURRENCED = DETECTION RAKING 19 The Design FMEA Document Item Design Responsibility Prepared By Model Number/Year Key Date FMEA Date Core Team FMEA Number The Design FMEA Document Item/Function Potential Failure Mode Potential Effect(s) of Failure Severity (S) Classification (CLASS) Potential Cause(s)/Mechanism(s) of Failure Occurrence (O) The Design FMEA Document (Con. 1)n Current Design Controlsn Detection (D)n Risk Priority Number (RPN)n Recommended Actionsn Responsibility and Target Completion Datesn Actions Taken The Process FMEA Document (Con. 2)n Process Function/Requirementsn Potential Failure Moden Potential Effect(s) of Failuren Severity (S)n Classification (CLASS)n Potential Cause(s)/Mechanism(s) of Failure n Occurrence (O)n Current Process Controls Limitations:n FMEA documents do not fix the identified problemn Def. of the action to fix the problemn Will not replace the basic problem-solving process. ?Questions?