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Innovative Approach to FMEA facilitation

Govind Ramu, P.Eng,ASQ CQMgr, CQE, CSSBB, CQA, CSQE, CRE,

ASQ Fellow,

QMS 2000 Principal Auditor IRCA (UK)

Past Section Chair Ottawa Valley- ASQ Canada

http://www.asq.org/sixsigma/about/govind.html
http://www.asq.org/sixsigma/about/govind.htmlhttp://www.asq.org/sixsigma/about/govind.html


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History of the FMEA

The FMEA discipline was developed in the United StatesMilitary in 1949 (Military Procedure MIL-P-1629, titled

Procedures for Performing a Failure Mode, Effects and

Criticality Analysis.

The first formal application of FMEA discipline was used in

aerospace in mid 60s. It was used as a reliability evaluation technique to determine

the effect of system and equipment failures. Failures were

classified according to their impact on mission success and

personnel/equipment safety. Reference: SAE J 1739 and AIAG.

The FMEA discipline was developed in the United StatesMilitary in 1949 (Military Procedure MIL-P-1629, titled

Procedures for Performing a Failure Mode, Effects andCriticality Analysis.

The first formal application of FMEA discipline was used inaerospace in mid 60s.

It was used as a reliability evaluation technique to determinethe effect of system and equipment failures. Failures were

classified according to their impact on mission success and

personnel/equipment safety. Reference: SAE J 1739 and AIAG.


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A structured approach to

Identify the way in which a design / process can fail to meet

critical customer requirements.

Estimating the risk of specific causes with regard to the failures.

Evaluating the Current control plan for preventing the failures fromoccurring.

Prioritizing the actions that should be taken to improve the design/

process.

A structured approach to

Identify the way in which a design / process can fail to meet

critical customer requirements.

Estimating the risk of specific causes with regard to the failures.

Evaluating the Current control plan for preventing the failures fromoccurring.

Prioritizing the actions that should be taken to improve the design/

process.

What is FMEA?


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FMEA is very beneficial to conduct while designing a product or

process.Design FMEA should be done during initial design of the product.

Process FMEA should be done during design of manufacturing

process.

Process FMEA can be performed for legacy products and processesalso if the process carry high risks to product quality, customer, safety,

etc.

FMEA is very beneficial to conduct while designing a product or

process.Design FMEA should be done during initial design of the product.

Process FMEA should be done during design of manufacturing

process.

Process FMEA can be performed for legacy products and processesalso if the process carry high risks to product quality, customer, safety,

etc.

When to use FMEA?


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Different Types of FMEA

An analyt ical technique used

primarily by design responsible

engineer/Team to assure

potential failure modes; causesand effects have been

addressed for design related

characteristics.

Design FMEA

An analyt ical technique used

primarily by manufacturing

responsible engineer/Team to

assure potential failure modes;causes and effects have been

addressed for process related

characteristics.

Process FMEA

System, Subsystem,

Component level FMEA are

possible scopes


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Definitions

Critical Characteristics are Special

Characteristics defined by

organization that affect customer

safety and/or could result in non-

compliance with government

regulations and thus require special

controls to ensure 100% compliance.

Critical Characteristics

Detection is an assessment of the likelihoodthat the Current Controls (design and process)

will detect the Cause of the Failure Mode or the

Failure Mode itself, thus preventing it from

reaching the Customer.

Detection

Severity is an assessment of how serious the

Effect of the potential Failure Mode is on the

Customer.

Severity

Occurrence is an assessment of the likelihood

that a particular Cause will happen and result

in the Failure Mode during the intended life anduse of the product.

Occurrence

The Criticality rating is the

mathematical product of

the Severity and

Occurrence ratings.

Criticality = (S) X (O). This

number is used to place

priority on items thatrequire additional quality

planning.

Criticality

The Risk Prior ity Number is a

mathematical product of thenumerical Severity, Occurrence,

and Detection ratings.

RPN = (S) X (O) X (D). This

number is used to place priority

on items than require additional

quality planning.

Risk Priority Number


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Definitions

A Function could be any

intended purpose of a

product or process. FMEA

functions are best

described in verb-noun

format with engineering

specifications.

Function

Failure Modes are sometimes described as

categories of failure. A potential Failure Modedescribes the way in which a product or

process could fail to perform its desired

function (design intent or performance

requirements) as described by the needs,

wants, and expectations of the internal and

external Customers.

Failure Mode

FMEA elements are identified or

analyzed in the FMEA process.

Common examples are Functions,

Failure Modes, Causes, Effects,

Controls , and Actions. FMEA

elements appear as column

headings in the output form.

FMEA Element

Customers are internal and

external departments, people, and

processes that will be adversely

affected by product failure.

Customer

A Cause is the means by

which a particular element

of the design or process

results in a Failure Mode.

Cause

An Effect is an adverse consequence that the

Customer might experience. The Customer

could be the next operation, subsequent

operations, or the end user.

Effect

Current Controls (design and process) are the

mechanisms that prevent the Cause of the

Failure Mode from occurring, or which detect

the failure before it reaches the Customer.

Current Controls


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Review design and process using a functional block diagram, system

design, architecture and process flow chart.

Use a brainstorming approach to gather potential failure modes. Use historical data from customer returns, complaints and internal

issues from comparable products or processes.

List potential effects, both internal and external, of failure.

Assign severity, occurrence and detection (SOD) rankings based onthe effect, probability of occurrence of the root cause and ability to

detect the root cause before the failure mode happens.

Calculate the risk priority number (RPN) by multiplying severity,occurrence and detection rankings. Also, calculate criticality by

multiplying severity and occurrence.

Prioritize the failure modes (risks) based on RPN score and/or

criticality. Take actions to eliminate or reduce the risks.

FMEA Traditional approach


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FMEA

DEVELOPMENTPROCESS

FMEA

DEVELOPMENTPROCESS

FMEA

Forms

FMEA

Forms

FMEATEAM

FMEATEAM

FMEA#

FMEA# Part No.

Part No.ProcessI.D.

ProcessI.D.

PreparedBy

PreparedByOwner

Owner Due DateDue Date

ProcessFunction

ProcessFunctionCoreTeam

CoreTeam Pot FailureMode

Pot FailureModeFMEADATE

FMEADATE FailureEffects

FailureEffects SeveritySeverity

OccurrenceOccurrencePot

Causes

Pot

Causes

ClassClass Current

Control

Current

Control

DetectionDetection

Flowchart

TRADITIONAL

APPROACH


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Major issues

Quality of the FMEA

Quantity of Completion

Fundamental issues- Bundlingof causes!

Fill it, Shut it, Forget it*!

* Courtesy: Famous 80s advertisement campaign from Hero Honda Motor cycle manufacturers India. (On fuel economy)


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During development:

Not understanding the fundamentals of failure mode effects analysis

(FMEA) development.Inadequate representation in the team from subject matter experts.

Failing to identify the right inputs for the FMEA.

Poor planning before assembling for brainstorming and failure ranking.

During implementation:

Breaking the sessions into weekly meetings (thus losing continuity).

Using severity, occurrence and detection (SOD) scales that are notrepresentative of the industry, product family or process group.

Failing to learn from the risks exposed at the component and module-

level FMEA while drafting at the system level FMEA.

Allowing the rigor of the tool to drive the intensity of initial interactions,causing fatigue for participants.

Pitfalls


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During implementation: (Continued)

Wasting time on risk-rating debates.

Failing to follow through on recommended actions.

Failing to drive actions across the board in a systemic way.Failing to integrate the learning from design and process FMEAs or to link to

control plans, critical to quality characteristics and critical to process

parameters.

During sustainability:Not incorporating the identified, mitigated risks into manufacturing

guidelines to be used for future product development.

Failure to keep the FMEA alive by including feedback from subsequent

stages of the product life cycle.

Pitfalls (Continued)


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Sources of data

Supplier caused

E.g. Out of Spec, non conformance, etc.

Process Control

E.g. Out of Spec, Contamination

Product or Process Changes

E.g. failure, etc.

Internal Ongoing Reliability issues

Periodic Surveillance

E.g. Out of Spec

Customer Returns- DPPM data

Product Design related

E.g. Performance, reliability, etc.

Process Design related

E.g. Opportunity for error

Process Control

E.g. Out of Spec, Contamination

Customer caused

E.g. damage, S/W error, etc.

Supplier caused

E.g. Out of Spec, non conformance, etc.

Customer complaints onproduct or system performance

With No product return or RMA

DFMEA / PFMEA

(Potential)

Failure mode-Effects-Causes

% Defective, Defects per Unit

Customer Complaints

Process control issues

E.g. traceability, yield, etc.

Supplier feedback

Product/Process Design RelatedE.g. tight unrealistic tolerances, Capability.

Similar sources of data from comparable

Products, processes of Organization

BODY OF KNOWLEDGE

Known Industry failure

-Technical journals, publications,

-Conferences, etc.

External Knowledge


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Scope Process (Process FMEA)

Formulate Cross functional Team

Understand Customer/Process Requirements.

Define the start and end of the Process

All team members to walk and observe the process.

Get the assemblers/ process operators to explain the process.

Team makes notes and observations.


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Brainstorm all potential causes for the

failure modes

INNOVATIVE APPROACH Inputs:Process Flow charts, Manufacturing WI,

Historical process defect pareto, lessons learned, Etc


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Brainstorming Software feature

Microsoft VISIO


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Brainstorm all potential local & end effects

for the failure modes


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Brainstorm all potential failure modes

Utilize process flow chart-break down each step.

Use knowledge of previous and existing parts/processes.

Review all quality information E.g.: Scrap, rework, RMA,etc.

Talk to internal and external customers.

Failure Modes are sometimes described as

categories of failure. A potential Failure Mode

describes the way in which a product or

process could fail to perform its desiredfunction (design intent or performance

requirements) as described by the needs,

wants, and expectations of the internal and

external Customers.

Failure Mode

An Effect is an adverse consequence that the

Customer might experience. The Customer

could be the next operation, subsequent

operations, or the end user.

Effect

Example:

Does not f it, Cannot load or fasten, poor

performance, intermittent failure erratic

operation.Example:

Fiber Damage, Contamination, hairline crack,Dimension oversize.


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Identify potential effects of failure

For each failure mode, identify the effect(s)

on the current or next process or customer

downstream in manufacturing/assembly process.

Describe the effects of failure in terms of what the customer

might notice or experience.


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Cause and Effect Cascade with an example

Design

Environmental

Exposure

Moisture

Corrosion

Poor Contact

(High

Resistance)

Insufficient

Current

Dim Bulb

Cause

Effect

Cause

Effect

Cause

Effect

CauseEffect

Cause

Effect

Cause

Effect

Cause = Design

Effect = Env. Exposure

Cause = Env. ExposureEffect = Moisture

Cause = Moisture

Effect = Corrosion

Cause = Corrosion

Effect = High Resistance

Cause = High ResistanceEffect = Insufficient Current

Cause = Insufficient Current

Effect = Dim Bulb

Courtesy: Elsmar Cove


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Determine severity rating

Severity is an assessment of the seriousness of

the effect of Potential failure mode to the customer.

Severity applies to effect only.

Note: Assigning severity rating should be performed as a team

Including customer representative and or Design FMEA engineer.

If the customer affected by a failure mode is a user outside the plant, team

Should consult them and assign the rating.


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Identify all potential causes of failure

How the failure could occur? Describe in terms of factors

That can be corrected or controlled.

Note: Experiments may have to be conducted to determine causes using technical

Problem solving.

There could be more than one cause for each failure!!

Example:Improper torque, Inaccurate gauging, inadequate lubrication, etc.

Management should have control on the cause identified. The cause

should be at the root level.


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Determine occurrence rating

Occurrence is how frequently the specific failure cause

Mechanism is projected to occur.

Note: If available from a similar process, statistical data should be used to determine

Occurrence ranking.

Define Current Controls

Systematic methods/devices in place to prevent or detectFailure modes or causes (before the effect happens).

Example: Poke-Yoke, automated control for setup verification


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Determine detection ranking

Detection is an assessment of the probability that the

current process control will detect a Potential cause.

Note: Random quality checks are unlikely to detect the existence of an isolated

Defect and should not influence the detection ranking. Sampling done on a

Statistical basis is a valid detection control.

Also assess the ability of the process control to detectLow frequency failure modes or prevent from going

Into the next process.


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Current Controls

Design and Process controls are grouped according to their purpose.

Type (1)

These controls prevent the Cause or Failure Mode from

occurring, or reduce their rate of occurrence.Type (2)

These controls detect the Cause of the Failure Mode and

lead to corrective action.Type (3)

These Controls detect the Failure Mode before the

product reaches the customer. The customer could be

the next operation, subsequent operations, or the enduser.

The distinction between controls that prevent failure (Type 1) and controls that detect failure (Types 2 and 3) is

important. Type 1 controls reduce the likelihood that a Cause or Failure Mode will occur, and therefore affect

Occurrence ratings. Type 2 and Type 3 Controls detect Causes and Failure Modes respectively, and therefore

affect Detection ratings.


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Calculate the Risk Priority Numbers

The Risk Priority Number is the product of

Severity (S) X Occurrence (O) X Detection (D) rankings.

This value should be used to rank order the concerns

In the process using Pareto. The RPN will be

between 1and 1000.

Criticality is severity multiplied by occurrence.

This is also an important metric.RPN can be reduced by improving the detection, but theprocess issue may remain intact. Criticality can bereduced only by improving the capability or redesign.


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Prioritize Corrective actions

Concentrate on the Highest RPNDo not lose sight on effects with high severity.

Think of how the occurrence can be reduced?

How the detection can be improved?

Where applicable use Mistake proofing techniques.Introduce changes in a controlled manner.


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Reassess rankings when action completed

FMEA must be a Live document.

Review Regularly.

Reassess rankings whenever changes made to product/process.Add any new defects or potential problems when found.


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References

Potential Failure Mode & Effects Analysis, fourth edition,Automotive Industry Action Group, 2008.

Govindarajan Govind Ramu, Metrics That TriggerActionable Discussions: Prioritize Process ImprovementsUsing Gauge R&R and SPC Capability, ASQ Six SigmaForum.

Traditionally, NGT is used to collect ideas:www.asq.org/learn-about-quality/idea-creation-tools/overview/nominal-group.html In FMEA development, itcan be used to collect scores of SOD.

Elsmar Cove archived fi le references.

BibliographyQuality Training Portal, Resource Engineering Inc., What You Need to

Know About Failure Mode and Effects Analysis (FMEA),

www.qualitytrainingportal.com/resources/fmea/index.htm.May 2009 QP Standards Outlook Dan Reid- Major Upgrade.
http://www.asq.org/forums/sixsigma/articles/mbb/mb_metrics_actionable_discussions1.htmlhttp://www.asq.org/forums/sixsigma/articles/mbb/mb_metrics_actionable_discussions1.htmlhttp://www.asq.org/forums/sixsigma/articles/mbb/mb_metrics_actionable_discussions1.htmlhttp://www.asq.org/forums/sixsigma/articles/mbb/mb_metrics_actionable_discussions1.htmlhttp://www.asq.org/learn-about-quality/idea-creation-tools/overview/nominal-group.htmlhttp://www.asq.org/learn-about-quality/idea-creation-tools/overview/nominal-group.htmlhttp://www.asq.org/learn-about-quality/idea-creation-tools/overview/nominal-group.htmlhttp://www.qualitytrainingportal.com/resources/fmea/index.htmhttp://www.qualitytrainingportal.com/resources/fmea/index.htmhttp://www.asq.org/learn-about-quality/idea-creation-tools/overview/nominal-group.htmlhttp://www.asq.org/learn-about-quality/idea-creation-tools/overview/nominal-group.htmlhttp://www.asq.org/forums/sixsigma/articles/mbb/mb_metrics_actionable_discussions1.htmlhttp://www.asq.org/forums/sixsigma/articles/mbb/mb_metrics_actionable_discussions1.htmlhttp://www.asq.org/forums/sixsigma/articles/mbb/mb_metrics_actionable_discussions1.html

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