Process Failure Mode Effect

Analysis

Northrop Grumman CorporationIntegrated Systems

CA/PA-RCA : Advanced Tool

2

Overview Objective

Failure Mode Effect Analysis (FMEA) – Provide a Basic familiarization with a tool that aids in quantifying severity, occurrences and detection of failures, and guides the creation of corrective action, process improvement and risk mitigation plans.

3

Agenda

FMEA History What IS FMEA

Definitions What it Can Do For You

Types of FMEA Team Members Roles FMEA Terminology Getting Started with an FMEA The Worksheet FMEA Scoring

4

Agenda Why does it always seem we have plenty

of time to fix our problems, but never

enough time to prevent the

problems by doing it right the first time?

5

FMEA History

This “type” of thinking has been around for hundreds of years. It was first formalized in the aerospace industry during the Apollo program in the 1960’s.

Initial automotive adoption in the 1970’s.

Potential serious & frequent safety issues.

Required by QS-9000 & Advanced Product Quality Planning Process in 1994.

Now adopted by many other industries.

For all automotive suppliers.

Potential serious & frequent safety issues or loyalty issues.

6

What is FMEA ?

Cause & effect, Root Cause Analysis, Fishbone Diagram Etc

Failure Mode Effect Analysis

7

What is FMEA ?

Definition: FMEA is an Engineering “Reliability Tool” That: Helps define, identify, prioritize, and eliminate known and/or

potential failures of the system, design, or manufacturing process before they reach the customer. The goal is to eliminate the Failure Modes and reduce their risks.

Provides structure for a Cross Functional Critique of a design or a Process

Facilitates inter-departmental dialog.

Is a mental discipline “great” engineering teams go through, when critiquing what might go wrong with the product or process.

Is a living document which ultimately helps prevent, and not react to problems.

8

What is FMEA ?

What it can do for you!

1.) Identifies Design or process related Failure Modes before they happen.

2.) Determines the Effect & Severity of these failure modes.

3.) Identifies the Causes and probability of Occurrence of the Failure Modes.

4.) Identifies the Controls and their Effectiveness.

5.) Quantifies and prioritizes the Risks associated with the Failure Modes.

6.) Develops & documents Action Plans that will occur to reduce risk.

9

Types of FMEAs ?

System/Concept “S/CFMEA”- (Driven by System functions) A system is a organized set of parts or subsystems to accomplish one or more functions. System FMEAs are typically very early, before specific hardware has been determined.Design “DFMEA”- (Driven by part or component functions) A Design / Part is a unit of physical hardware that is considered a single replaceable part with respect to repair. Design FMEAs are typically done later in the development process when specific hardware has been determined. Process “PFMEA”- (Driven by process functions & part characteristics) A Process is a sequence of tasks that is organized to produce a product or provide a service. A Process FMEA can involve fabrication, assembly, transactions or services.

10

Types of FMEAs ?

System/Concept “S/CFMEA”- (Driven by System functions) A system is a organized set of parts or subsystems to accomplish one or more functions. System FMEAs are typically very early, before specific hardware has been determined.Design “DFMEA”- (Driven by part or component functions) A Design / Part is a unit of physical hardware that is considered a single replaceable part with respect to repair. Design FMEAs are typically done later in the development process when specific hardware has been determined. Process “PFMEA”- (Driven by process functions & part characteristics) A Process is a sequence of tasks that is organized to produce a product or provide a service. A Process FMEA can involve fabrication, assembly, transactions or services.

11

The FMEA Team Roles

FMEA Core Team4 – 6 Members

Expertise in Product / ProcessCross functional

Honest CommunicationActive participation

Positive attitudeRespects other opinions

Participates in team decisions

FMEA Core Team4 – 6 Members

Expertise in Product / ProcessCross functional

Honest CommunicationActive participation

Positive attitudeRespects other opinions

Participates in team decisions

Champion / SponsorProvides resources & support

Attends some meetingsPromotes team efforts

Shares authority / power with teamKicks off team

Implements recommendations

Champion / SponsorProvides resources & support

Attends some meetingsPromotes team efforts

Shares authority / power with teamKicks off team

Implements recommendations

RecorderKeeps documentation of teams efforts

FMEA chart keeperCoordinates meeting rooms/time

Distributes meeting rooms & agendas

RecorderKeeps documentation of teams efforts

FMEA chart keeperCoordinates meeting rooms/time

Distributes meeting rooms & agendas

Facilitator“Watchdog“ of the process

Keeps team on trackFMEA Process expertise

Encourages / develops team dynamicsCommunicates assertively

Ensures everyone participates

Team Leader“Watchdog” of the project

Good leadership skillsRespected & relaxed

Leads but doesn’t dominateMaintains full team participation

Typically lead engineer

12

FMEA Terminology

1.) Failure Modes: (Specific loss of a function) is a concise

description of how a part , system, or manufacturing process may potentially fail to perform its functions.

2.) Failure Mode“Effect”: A description of the consequence or Ramification of a system or part failure. A typical failure mode may have several “effects” depending on which customer you consider.

3.) Severity Rating: (Seriousness of the Effect) Severity is thenumerical rating of the impact on customers.

When multiple effects exist for a given failure mode, enter the worst case severity on the worksheet to calculate risk.

4.) Failure Mode“Causes”: A description of the design or processdeficiency (global cause or root level cause) that results in the failure mode .

You must look at the causes not the symptoms of the failure. Most failureModes have more than one Cause.

13

FMEA Terminology (continued)

5.) Occurrence Rating: Is an estimate number of frequencies or cumulative number of failures (based on experience) that will occur (in our design concept) for a given cause over the intended “life of the design”.

6.) Failure Mode“Controls”: The mechanisms, methods, tests, procedures, or controls that we have in place to PREVENT the Cause of the Failure Mode or DETECT the Failure Mode or Cause should it occur . Design Controls prevent or detect the Failure Mode prior to engineering release

7.) Detection Rating: A numerical rating of the probability that a given set of controls WILL DISCOVER a specific Cause of Failure Mode to prevent bad parts leaving the facility or getting to the ultimate customer.

Assuming that the cause of the failure did occur, assess the capabilities of the controls to find the design flaw..

14

FMEA Terminology (continued)

8.) Risk Priority Number (RPN): Is the product of Severity, Occurrence, & Detection. Risk= RPN= S x O x D Often the RPN’s are sorted from high to low for consideration in the action planning

step (Caution, RPN’s can be misleading- you must look for patterns).

9.) Action Planning: A thoroughly thought out and well developed FMEA With High Risk Patterns that is not followed with corrective actions has little or no value, other than having a chart for an audit Action plans should be taken very seriously. If ignored, you have probably wasted much of your valuable time. Based on the FMEA analysis, strategies to reduce risk are focused

on:

Reducing the Severity Rating. Reducing the Occurrence Rating. Reducing the detection Rating.

15

Determine“Controls”

Detection Rating

Determine“Effects” ofThe Failure

ModeSeverity Rating

Getting Started on FMEA

What Must be done before FMEA Begins!

Determine“Causes” ofThe Failure

ModeOccurrence Rating

DetermineProduct or Process

Functions

Determine Failure Modes

of Function

Understand yourCustomer

Needs

Develop & EvaluateProduct/Process

Concepts

Create an Effective FMEA Team

Develop andDrive

Action Plan

Ready?

1

3

2 4 6

=QFD

=Brain Storming

=4 to 6 Consensus Based MultiLevel Experts

= What we are and are not working

Define the FMEAScope

5Calculate &Assess Risk

6

7

16

The FMEA Worksheet

Product or

Process

Failure Mode

Failure Effects

SEV

CausesOCC

ControlsDET

RPN

Actions / Plans

Resp. & Target

Complete Date

pSEV

pOCC

pDET

pRPN

1 62 3 4 5 7

DetermineProduct or Process

Functions

Determine Failure Modes

of Function

Determine“Effects” ofThe Failure

ModeSeverity Rating

Determine“Causes” ofThe Failure

ModeOccurrence

Rating

Determine“Controls”Detection

Rating

Calculate &

Assess Risk

Develop and

DriveAction Plan

If an FMEA was created during the Design Phase of the Program, USE IT!Create an Action Plan for YOUR ROOT CAUSE

and Re-Evaluate the RPN Accordingly

17

FMEA ScoringSeverity

Severity of Effect Rating

May endanger machine or operator. Hazardous without warning 10

May endanger machine or operator. Hazardous with warning 9

Major disruption to production line. Loss of primary function, 100% scrap. Possible jig lock and Major loss of Takt Time 8

Reduced primary function performance. Product requires repair or Major Variance. Noticeable loss of Takt Time 7

Medium disruption of production. Possible scrap. Noticeable loss of takt time. Loss of secondary function performance. Requires repair or Minor Variance 6

Minor disruption to production. Product must be repaired. Reduced secondary function performance. 5

Minor defect, product repaired or "Use-As-Is" disposition. 4Fit & Finish item. Minor defect, may be reprocessed on-line. 3

Minor Nonconformance, may be reprocessed on-line. 2

Non

e

No effect 1

Ext

rem

eH

igh

Mod

erat

eL

ow

18

FMEA ScoringOccurrence

Likelihood of OccurrenceFailureRate

Capability(Cpk) Rating

1 in 2 < .33 10

1 in 3 > .33 9

1 in 8 > .51 8

1 in 20 > .67 7

1 in 80 > .83 6

1 in 400 > 1.00 5

1 in 2000 > 1.17 4

Process is in statistical control. 1 in 15k > 1.33 3

Low Process is in statistical control. Only isolated

failures associated with almost identical processes.1 in 150k > 1.50 2

Rem

ote

Failure is unlikely. No known failures associatedwith almost identical processes. 1 in 1.5M > 1.67 1

Failure is almost inevitable

Process is not in statistical control.Similar processes have experienced problems.

Process is in statistical control but with isolated failures.Previous processes have experienced occasional

failures or out-of-control conditions.

Ver

y H

igh

Hig

hM

oder

ate

19

FMEA ScoringDetection

Likelihood that control will detect failure RatingV

ery

Low

No known control(s) available to detect failure mode. 10

9

8

7

6

5

4

3

2

1

The process automatically detects failure.Controls will almost certainly detect the existence ofa failure.

Controls have a good chance of detecting the existenceof a failure

Low

Mod

erat

eH

igh

Ver

y H

igh

Controls have a remote chance of detecting the failure.

Controls may detect the existence of a failure

20

FMEA ScoringRPN or Risk Priority Number

Severity x Occurrence x Detection=

RPN

The Calculation !

21

Failure Modes & Effect Analysis(FMEA) Part or Process Improvement FMEA is a technique utilized to define, identify, and eliminate

known or potential failures or errors from a product or a process. Identify each candidate Part or Process, list likely failure

mode, causes, and current controls Prioritize risk by using a ranking scale for severity,

occurrence, and detection Mitigate risk – Can controls be added to reduce risk?

Recalculate RPN. Characteristics with high Risk Priority Numbers should be

selected for Improvement and Action Plans Created Recalculate RPN After Completion of Action Plans to Validate

ImprovementsProduct

or Process

Failure Mode

Failure Effects

SEV

CausesOCC

ControlsDET

RPN

Actions / Plans

Resp. & Target

Complete Date

pSEV

pOCC

pDET

pRPN

Hole Drilling

Oversize Hole

Unable toInstall BPFastener

WrongDrill Bit

Used

Ball GageVisual Insp5 8 3

120 Kit Drill

Bits010103 5 11 5

22

Failure Modes & Effect Analysis

Questions?Call or e-mail:

Kevin M. Treanor Bob Ollerton310-863-4182 310-332-1972/310-350-9121kevin.treanor@ngc.com robert.ollerton@ngc.com