GE 6757 TOTAL QUALITY MANAGEMENT Faculty R.Suresh kumar Assistant Professor(Sr.Gd) Department of Mechanical Engineering

Failure Mode Effect Analysis FMEA Failure Mode Effect Analysis

FMEA Failure Mode and Effect Analysis is also known as risk analysis. It is a preventive measure to systematically display the causes, effects and possible actions regarding observed failures. Is an engineering technique used to define, identify and eliminate known or potential failures, problem, errors. It is before-the-event action Is a never ending process improvement tool.

FMEA - OBJECTIVES Find failures and prevent them. Priorities failures and attempts to eliminate them.

TYPES OF FMEA System FMEA - Design FMEA - Design FMEA Process FMEA - Service FMEA - Equipment FMEA - Process FMEA Maintenance FMEA - Concept FMEA - Design FMEA Environmental FMEA - Process FMEA

BENEFITS OF FMEA Improve product/process reliability and quality. Increase customer satisfaction. Early identification/elimination of failure modes. Prioritize product/process deficiencies. Capture engineering/organisation knowledge Document and track the action taken to reduce risk Focus for improved testing and development Act as catalyst.

INPUTS FOR FMEA People inputs: FMEA is a team work. The team should have assembly engineer, manufacturing engineer, material engineer, quality engineer, service engineer, suppliers and the customer. 2. Data inputs: Product and process specifications, reliability data, customer priority data, process variability data, process descriptions and inspection data.

STAGES OF FMEA Stage 1: Specifying Possibilities Functions ii) Possible failure mode iii) Root causes iv) Effects v) Detection/Prevention. Stage 2: Quantifying Risks Probability of cause ii) Severity of effect iii) Effectiveness of control to prevent cause iv) Risk Priority Number (RPN)

STAGES OF FMEA Stage 3: Correcting High Risk Causes Prioritizing work Detailing action Assigning action responsibility Check points on completion Stage 4: Re-evaluation of Risk i) Recalculation of risk priority number

FMEA PROCEDURE Describe the product/process and its function Create a block diagram of the product/process Complete the header of the FMEA form worksheet List product/process functions Identify failure modes failure mode includes corrosion failure, fatigue, deformation, cracking, electrical short or open etc.. Describe the potential failure effects defined as the result of a failure mode on the function of the product/process ex: injury to the user, impaired operation, poor appearance, odour, noise etc..

FMEA PROCEDURE 7. Establish a numerical ranking for the Severity(S) of the effect S is the assessment of the seriousness of the failure effect standard scale uses 1 for no effect and 10 for very serious effect. 8. The CLASS column is filled Used to classify any special product characteristics for components that may require additional process controls. 9. Identify the potential causes/mechanisms of failure 10. The probability factor “Occurrence” (O) It is the chance that one of the specific causes will occur. Standard scale uses 1 to represent not likely and 10 to indicate inevitable.

FMEA PROCEDURE 11. Identify current controls (design or process) 12. Determine the likelihood of detection (D) It is the assessment of the likelihood that the current controls will detect the cause of failure mode 1 used for certain of detection and 10 for uncertainty of detection. 13. Review Risk Priority Number (RPN) RPN = S x O x D 14. Determine recommended actions 15. Assign responsibility and target completion date 16. Indicate action taken After action, re-assess the severity, occurrence and detection and revise the RPN 17. Update the FMEA

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