Failure Mode & Effect Analysis (FMEA) - PowerPoint Presentation

Slide1

Failure Mode & Effect Analysis (FMEA) in Half the Time Howard C Cooper, MS, DFSS-BBMay 13th, 2014

INCOSE Michigan

– May Dinner MeetingSlide2

IntroductionFailure Mode & Effects Analysis (FMEA) is an analytical tool and structured method to:Recognize and evaluate the potential failure of a product/process and its effects

Identify and prioritize actions which could eliminate or reduce the chance of a potential failureDocument the process

Before they are “baked” into a product

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Common Types of FMEADesign FMEAIdentify and mitigate potential design problems early in the design cycleProcess / Manufacturing FMEA Improve quality and reliability, during set-up of initial manufacturing processProblem Solving / Six Sigma FMEAUnderstand failure modes and effects to identify and solve quality or reliability issues

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Where FMEA is Used

Common FMEA Usage

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Failure Mode

Example Design FMEA

Prioritize Failure Modes by Risk Priority Number

SEV X OCC X DET = (RPN)

Items within the system being analyzed

FM & Effects of each failure mode

Severity

Root Cause

Relative Occurrence

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ItemSlide6

Item

Potential Failure Mode

Potential Effect(s) of Failure

Sev

Potential Cause(s)/Mechanism(s) of Failure

Occur

Current Process Controls Detection

Detec

RPN

Process Function

3 - Front Door L.H.

Manual application

of chromate conversion coatings on exposed aluminum substrate

(to

retard

corrosion)

Insufficient

chromate coating

over

specified surface.

Deteriorated life of

part leading

to:

- Unsatisfactory appearance due to rust through paint over time.

- Impaired function of

hardware

.

5Manually inserted spray head not inserted far enough.3Visual check each hour - 1/shift for film thickness (depth meter) and coverage.575Spray head clogged- Viscosity too high- Temperature too low- Pressure too low.2Visual check each hour - 1/shift for film thickness (depth meter) and coverage.330Spray head deformed due to impact.2Visual check each hour - 1/shift for film thickness (depth meter) and coverage.220Spray time insufficient.1Operator instructions and lot sampling (10 doors/shift) to check for coverage of critical areas.210

Example Process FMEA

Steps within the process being analyzed

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Typical FMEA ProcessAssemble team of people with diverse knowledge of process & productBound the problemIdentify functions

Identify potential failure modesPopulate FMEA detailsPrioritize failure modes based on RPN

Mitigate failure modes

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Mission to Improve FMEA Development

Challenge

Current FMEA problems:

Opportunity:

Time consuming

Rapid (>

2x faster)

High rate of missed critical failure modes

Critical failure modes are given top-priority

Ad hoc identification of failure modes

Process-driven identification of

all failure modes

Disjointed, undirected time-consuming discussion

Focused,

efficient

development effort

Allows prioritization only after FMEA development

Prioritization

can happen before FMEA development

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Improved FMEA ProcessIn 2012, GDLS developed process to prepare ‘efficient’ and ‘effective’ FMEA at greatly reduced time and costProcess involves four primary tools:

Major innovation:

Decomposition Table identifies and prioritizes Failure Modes (FMs) into FMEA. Focuses analysis on critical failure modes

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Step 1: Bound the System

Identifies and

verifies:

System functions: lines

crossing the

dotted boundary

“Items”

within the dotted line system

boundary

What

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Boundary Diagram / Process FlowSlide11

Step 2: Characterize the Process

Green blocks

, identify functions of the system (or process)

Yellow blocks ~

Noise Factors,

Blue block,

Control Factors

,

Pink blocks ~

Error States

Why

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What (From Boundary Diagram)

P-DiagramSlide12

Outstanding Problem & OpportunityBoundary or Process Flow Diagram Identifies “Items” for the FMEA, but not the Failure Modes (FM) of those “items”P-Diagram Identifies system functions or requirements (even noise factors) but not the function or FMs of the “items”Opportunity

Develop a table that will identify and link “items” to their functions, and to their functional FMs

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Step 3: Map Functions to Failure Modes

System Functions

P-Diagram

Boundary / Process Diagram

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Step 3: Map Functions to Failure Modes

System Functions

P-Diagram

Boundary / Process Diagram

Need to Identify Item / HW Functions

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Step 3: Map Functions to Failure Modes

System Functions

P-Diagram

Boundary / Process Diagram

Identify Functions

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Step 3: Map Functions to Failure Modes

System Functions

P-Diagram

Boundary / Process Diagram

Identify Functions

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Step 3: Map Functions to Failure Modes

System Functions

P-Diagram

Boundary / Process Diagram

Identify Functions

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System Functions

Decomposition Table Structures FMEA

From

B-Diagram or Pr-Flow Chart

3-4

FMs per

Function

“

X

” indicates a

Function (and

4 FMs in the

FMEA)

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functions translate to FMsSlide19

3 Purposes of the Decomposition Table

Ensures all

items

are captured into the

FMEA

Ensures multiple function items

and their potential

failure modes are

identified into the

FMEA

Provides

opportunity to identify and prioritize

by criticality of hardware or process functions

before populating

failure modes into

the

FMEA

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System

Decomposition Table Prioritizes Functions

Criticality # rather than “X”

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Preparation Flow into Decomp Table

1.

P-Diagram

Ideal Functions

– to Design Functions

in F-H

Decomp

.

2.

B-Diagram

or Process Flow inner blocks go to

Decomp

. Table

3.

Identify all

‘Item’ Functions

needed to accomplish each

System Function

4.

Mark with an “X” or

with a “Criticality #”

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SystemSlide22

Step 4: Use

Decomp

Table to Fill FMEA

FMEA

filled in from F-H

Decomp

Table

1

1

2

2

3

3

4

4

1

System

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1

3

2Slide23

Pareto Chart (80/20 Rule)

Benefits of Improved FMEA Development

Four Step FMEA Process:

Organizes and speeds FMEA failure mode identification

Ensures all hardware-functions and FMs are identified

Prioritizes critical hardware-functions for FMEA analysis

Provides power of 80/20 Rule on FMs for best Reliability Growth

Focuses attention and time on mitigation of “significant few” (the most critical failure modes (FMs)

F-H

Decomp

Table now

being used on multiple GDLS

Contracts:

for

DFR, to facilitate

earlier diagnostics planning,

to

meet

Weight and Testability Requirements

Addressing most critical FMs yields greatest reliability growth.

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Cost Savings Attributed to New Process

Before

vs

, After Facilitator Cost

Savings on Facilitator Cost

Facilitator Savings X 3 for FMEA Team, X 3 Programs in 2013 = Total Savings

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Questions?

Presenters:

Howard C Cooper, MS,

DFSS-BB

DFR Reliability Engineer

cooperh@gdls.com

Mark Petrotta, MS, DFSS-MBB

Engineering Process Excellence

petrotta@gdls.com