1/9/20151

RAJASHREE POLYFIL(A DIV. OF CENTURY ENKA LTD.)

Failure Modes Effect AnalysisFailure Modes Effect Analysis

(FMEA)(FMEA)

BY : PANNALAL SONIBY : PANNALAL SONIBY : PANNALAL SONI

1/9/20152

Objectives of discussion

2

To understand the use of Failure Modes Effect Analysis (FMEA)

To learn the steps to developing FMEAs

To summarize the different types of FMEAs

To learn how to link the FMEA to our Process tools

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Type :

3

System - focuses on global system functions Design - focuses on components and subsystems Process - focuses on manufacturing and assembly processes Service - focuses on service functions Software - focuses on software function

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Benefits

4

Allows us to identify areas of our process that most impact our customers satisfaction (in terms of QMS)

Allows us to identify areas of our process that most impact our production quantity & quality may lead to major ecomonic loss

Helps us identify how our process system is most likely to fail

Points to process failures that are most difficult to detect

Points to take preventive actions and make alternate arrangement of most common & critical system/process/tools /equipments failure and its detection

Enable us to manage business risk (Financial, market, healht & safety etc.)

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What Is A Failure Mode?

5

What What

Can Go Can Go

Wrong?Wrong?

Failure modes and effects analysis (FMEA) is a step-by-step approach for identifying all possible failures in a design, a manufacturing or assembly process, or a product or service.

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FMEA: A Team Tool

6

A team approach is necessary.

Team should be led by the Process Owner who is the responsible manufacturing or technical person, or other similar individual familiar with FMEA.

Team Input Required

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FMEA Procedure

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1. 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 effects

Select a severity level for each effect

3. Identify potential causes of each failure mode

Select an occurrence level for each cause

4. List current controls for each cause

Select a detection level for each cause

Process Steps

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FMEA Procedure (Cont.)

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5. 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 10

7. Assign the predicted severity, occurrence, and detection levels and compare RPNs

Process Steps

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Severity, Occurrence, and Detection

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SeveritySeverity Importance of the effect on customer requirements Importance of t he effect on business collapse Importance of the effect on Production loss Importance of the effect on Quality of product etc.

OccurrenceOccurrenceFrequency with which a given cause occurs and

creates failure modes (obtain from past data if possible)

DetectionDetectionThe ability of the current control scheme to detect

(then prevent) a given cause (may be difficult to estimate early in process operations).

Analyzing Failure & Effects

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Rating Scales

10

There are a wide variety of scoring “anchors”, both quantitative or qualitative

Two 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 may allow for better precision in

estimates and a wide variation in scores (most common)

Assigning Rating

Weights

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Rating Scales (Example)

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Severity1 = Not Severe, 5 = Very Severe

Occurrence1 = Not Likely, 5 = Very Likely

Detection1 = Easy to Detect, 2 = Not easy to Detect

Assigning Rating

Weights

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Severity :

Very Low – 01, Low – 02, Moderate – 03, High – 04, Very High – 05

Consequences :

Very Low – 01, Low – 02, Moderate – 03, High – 04, Very High – 05

Detection :

F – 01, Low – 02 (Available or Identify need)

Rating Scales (Example)

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Falure Impact Rating

1 to 4 Do not required any alternate

5 to 9 No alternate solution is required but be careful to manage & maintain existing system

10 to 18 No special alternate solution is required

25 to 32 Special alternate solution should available in the company

50 Alternate Solution must be available at all time at the location of failure

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Risk Priority Number (RPN)

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RPN is the product of the severity, occurrence, and detection scores.

Severity Occurrence Detection RPNRPNX X =

Calculating a Composite

Score

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SeveritySeverity Occurrence Occurrence Detection (F/L)Detection (F/L) RPNRPN

11 11 11 11

22 22 11 44

33 33 11 99

44 44 11 1616

55 55 11 2525

11 11 22 22

22 22 22 88

33 33 22 1818

44 44 22 3232

55 55 22 5050

11 55 11 55

22 44 11 88

33 33 11 99

44 22 11 88

55 11 11 55

11 55 22 1010

22 44 22 1616

33 33 22 1818

44 22 22 1616

55 11 22 1010

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The FMEA Form

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Identify failure modes and their effects

Identify causes of the failure modesand controls

Prioritize Determine and assess actions

A Closer Look

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Action after FMEAAction after FMEA

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Prepare Failure Management Plan to : Improve Detection Improve existing failure management systemSuggest substitute to manage failureSuggest alternate system to manage failure

Key Points

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Example Process Equipment : Extruder

Identify Failure Mode (All possible failure that may impact in

product quality & quantity and safety)

Identify Detection neecd (or available detection suitability)

Identify Occurances (Probabilities on the base of past

incidents/failures)

Identify Impact in terms of product quantity, quality, safety etc

Calculate RPN

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Example Prioritise to task

See current control suitability

Suggest to improve (Detection, Alternate system etc.) the

system to manage the loss due to failure

Decide Target

Delegate Responsibility & Authority

Review the plan

Improve the plan

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