F.M.E.A (Failure Mode and Effect Analysis)

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F.M.E.A (Failure Mode and Effect Analysis)

• Chapter 14
• Ronette Braithwaite
• Tom Plotner

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GOALS

• F.M.E.A.
• What is it?
• Why is it used?
• How it is used.
• Reliability
• What is it?
• Why it is important.
• Block Diagrams

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How are we going to accomplish the goals?

• Implement quality!

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• Survey

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WHAT IS F.M.E.A??

• FMEA is an analytical technique that combines the
  technology and experience of people in
  identifying foreseeable failure modes of a
  product or process and planning for its
  elimination .
• FMEA can be explained as a group of activities
  intended to
• Recognize and evaluate the potential failure of a
  product or process and its effects
• Identify actions that could eliminate or reduce
  the chance of potential failures
• Document the process

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Cont.

• FMEA attempts to detect the potential
  product-related failure modes
• FMEA uses occurrence and detection probability
  criteria in conjunction with severity criteria to
  develop risk prioritization numbers for
  prioritization of corrective action
  considerations
• FMEA is a team effort which the engineer has to
  involve the assembly, manufacturing, materials,
  quality, service, supplier, and the next customer
  (internal or external)

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Benefits of FMEA

• Improves the quality, reliability, and safety of
  products / services / machinery and processes
• Improves company image and competitiveness
• Increases customer satisfaction
• Reduces product development timing and cost /
  support integrated product development
• Documents and tracks action taken to reduce risk
• Reduces potential for Warranty concerns
• Integrates with Design for Manufacturing
  Assembly techniques

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Several types of F.M.E.A design FMEA, process
FMEA, equipment FMEA, maintenance FMEA, concept
FMEA, service FMEA, system FMEA, environmental
FMEA, and others.

• Design FMEA
• Identifies known and foreseeable failure modes
• Establishes priorities based on expected failures
  and the severity of those failures
• Reduces development time and the cost of
  manufacturing process

• Process FMEA
• Identifies potential failure modes prior to
  operation of the process
• Helps to establish priorities according to the
  relative impact on the internal or external
  customer
• Helps to identify potential manufacturing or
  assembly causes in order to establish controls
  for occurrence reduction and detection

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Reliability

• Reliability defined
• The probability of a product to perform as
  expected for a certain period of time, under the
  given operating conditions, and at a given set
  for product performance characteristics.

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Why is reliability important?

• Reputation
• Customer Satisfaction
• Warranty Costs
• Repeat Business
• Cost Analysis
• Customer Requirements
• Competitive Advantage

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• What is the difference between Quality and
  Reliability?

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TAKE A BREAK!!!!

• Come back in about
• 10-15 minutes

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Block Diagram

• Is a simple, specialized, high-level type of
  flowchart.
• Provides a quick and uncomplicated overview of a
  process.
• Is used to design new processes or to simplify
  and understand existing processes.
• Is a starting point for process improvement.
•  

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Simple Block Diagram
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Complex Block Diagram CELL PHONE

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ACTIVITY
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4 Stages of FMEA

• Specifying Possibilities
• Functions
• Possible Failure Modes
• Root Causes
• Effects
• Detection/Prevention
• Quantifying Risk
• Probability of Cause
• Severity of Effect
• Effectiveness of Control to Prevent Cause
• Risk Priority Number

• Correcting High Risk Causes
• Prioritizing Work
• Detailing Action
• Assigning Action Responsibility
• Check Points on Completion
• Re-evaluation of Risk
• a. Recalculation of Risk Priority Number

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• Design FMEA
• View Handout

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Failure Mode And Effect Analysis(Design FMEA)

• FMEA Number______________
• Page___________of__________
• Item ____________ Design Responsibility___________
  Prepared By _______________
• Mode Number/Year________Key Date__________FMEA
  Date (Orig.)____(Rev.)____
• Core Team_________________________________________
  _____________________

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Item/ Function Potential Failure Mode Potential Effect(s) of Failure S C L A S S Potential Causes(s)/ Mechanism(s) of Failure O Current Design Controls D R P N

• List the functions of the item
• Function should be written in verb-noun context
• Each function must be measurable
• Example
• Must hold an extra large coffee (16 oz)
• Heat transmission of less than xx deg

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Item/ Function Potential Failure Mode Potential Effect(s) of Failure S C L A S S Potential Causes(s)/ Mechanism(s) of Failure O Current Design Controls D R P N

• Failure modes should be described in technical
  terms
• Avoid to many details
• Example
• Does not hold 16 oz.
• Transmits heat too quickly

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Item/ Function Potential Failure Mode Potential Effect(s) of Failure S C L A S S Potential Causes(s)/ Mechanism(s) of Failure O Current Design Controls D R P N

• Effects must be listed from the customers point
  of view
• Also state whether the failure will impact
  personal safety or break any product regulations
• Many effects may exist for each failure mode
• Example
• Insufficient quantity of coffee
• Must fill too often
• Injury to person - burn

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Item/ Function Potential Failure Mode Potential Effect(s) of Failure S C L A S S Potential Causes(s)/ Mechanism(s) of Failure O Current Design Controls D R P N

• View severity chart
• The severity applies only to the effect of the
  failure, not the potential failure mode
• If a severity of 9 or 10 is selected an action
  should be considered before continuing
• Example
• Insufficient quantity of coffee severity 5
• Must fill too often
• Injury to person (burn) severity 10

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Item/ Function Potential Failure Mode S C L A S S Potential Causes(s)/ Mechanism(s) of Failure O Current Design Controls D R P N

• Classify any special product characteristics for
  components, subsystems, or systems that may
  require additional process controls.

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Item/ Function Potential Failure Mode Potential Effect(s) of Failure S C L A S S Potential Causes(s)/ Mechanism(s) of Failure O Current Design Controls D R P N

• Must be listed completely and consciously
• There is usually more than one cause of failure
  for each failure mode
• Causes must be identified for a failure mode, not
  an individual effect
• Example
• Insulation material too thick
• Inside cup sized incorrectly
• Insufficient insulation

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Item/ Function Potential Failure Mode Potential Effect(s) of Failure S C L A S S Potential Causes(s)/ Mechanism(s) of Failure O Current Design Controls D R P N

• View occurrence chart
• Occurrence is based on the chance that one of the
  specific causes/mechanisms will occur
• Each cause must be rated on the probability of
  occurrences as it contributes to each failure
  mode
• Example
• Insulation material too thick occurrence 5
• Inside cup sized incorrectly occurrence 2
• Insufficient insulation occurrence 5

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Item/ Function Potential Failure Mode Potential Effect(s) of Failure S C L A S S Potential Causes(s)/ Mechanism(s) of Failure O Current Design Controls D R P N

• The activities that assure the design sufficiency
  for the failure mode or mechanism are listed
• Activities may include prevention measures,
  design validation, and design verification
• Three types of design controls
• Prevent the cause/mechanism or failure mode
  effect from occurring or reduce the rate of
  occurrence
• Detect the cause/mechanism and lead to corrective
  actions
• Detect only the failure mode

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Item/ Function Potential Failure Mode Potential Effect(s) of Failure S C L A S S Potential Causes(s)/ Mechanism(s) of Failure O Current Design Controls D R P N

• The first type is the preferred method to use
• Example
• Engineering specifications preventive control
• Historical data preventive control
• Functional testing detective control

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Item/ Function Potential Failure Mode Potential Effect(s) of Failure S C L A S S Potential Causes(s)/ Mechanism(s) of Failure O Current Design Controls D R P N

• View detection chart
• Detection is the value assigned to each of the
  detective controls
• Example
• Engineering specifications no detection value
• Historical data no detection value
• Functional testing detection 3

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Item/ Function Potential Failure Mode Potential Effect(s) of Failure S C L A S S Potential Causes(s)/ Mechanism(s) of Failure O Current Design Controls D R P N

• RPN (S) x (O) x (D)
• Values for the RPN can range from 1 to 1000
• RPN is used to rank the various concerns on the
  document
• Example
• Insufficient quantity of coffee severity 5,
  Inside cup sized incorrectly occurrence 2,
  Functional testing detection 3
• S 5 O 2 D 3 RPN 30
• Injury to person (burn) severity 10,
  Insufficient insulation occurrence 5,
  Functional testing detection 3
• S 10 O 5 D 3 RPN 150

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Recommended Actions Responsibility and Target Completion Dates Action Results Action Results Action Results Action Results Action Results
Actions Taken S E V O C C D E T R P N

• Recommended actions should be focused on design,
  and directed toward justifying the cause of
  failure mode, or eliminating the failure mode
• Always begin with the concern with the greatest
  RPN and working in descending order

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Recommended Actions Responsibility and Target Completion Dates Action Results Action Results Action Results Action Results Action Results
Actions Taken S E V O C C D E T R P N

• All recommended actions must have a person
  assigned responsibility for completion of the
  action
• There must be a completion date accompanying each
  recommended completion

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Recommended Actions Responsibility and Target Completion Dates Action Results Action Results Action Results Action Results Action Results
Actions Taken S E V O C C D E T R P N

• A brief description of the actual action and its
  effective date should be entered
• Re-estimate the resulting severity, occurrence,
  and detection rankings after the corrective
  actions have been identified
• Recalculate and record the resulting RPN

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Process FMEA
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ACTIVITY
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QUIZ
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Occurrence numbers tell

• How bad a failure is
• The likelihood of completing the FMEA
• The chance of detecting a failure
• The probability of a failure

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FMEA stands for _________ Mode and Effects
Analysis

• Founded
• Failure
• Function
• Fart

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RPN development is the reason FMEAs are performed

• True
• False

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Reliability is important to external and internal
customers?

• True
• False

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There are only two types of FMEAs Design and
Process

• True
• False

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Design FMEA should always begin with

• Risk priority number
• FMEA team
• Block diagram
• Failure rate

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Is FMEA a team effort?

• True
• False

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Does an organization need to implement FMEA to
achieve quality?

• True
• False

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Design FMEA should always start with a _________.

• FMEA Team
• FMEA evaluation
• Block diagram
• Quality function deployment

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Are you comfortable in conducting your own FMEA
document ?

• TRUE