1. Failure Effect Mode AnalysisBy
Rajeev
Kishore
Uros

2. Great question; a confusion in estimation
How a raw egg bounce?

3. Tacoma Bridge Collapse
Gondola FMEA

4. Introduction to FMEA
To introduce new products or manufacturing processes successfully in a cost-effective manner, resources should be allocated up-front to prevent problems.
Fixing the problem after a product is manufactured is more expensive than it is to prevent them.

5. Benefits of FMEA Reduce the number of engineering changes
Reduce product development time
Lower start-up cost, and reduces warranty
Greater customer satisfaction
Increased cooperation and teamwork between various functions
A well-documented project history and information database

7. Do you know?
“Failure Modes...” is a misnomer — some sources now call FMEA by another name: “Fault Hazard Analysis.”

8. Reliability Failures are expensive
System flakiness is a major source of user frustration
- 25% in survey have seen peers
kicking their computers
- 2% claim to have hit the person
next to them in their frustration

9. Failures are not very well understood
No Publicly available data on failures on real systems
WHY?

10. Different types of FMEA
Design (DFMEA): technique used primarily by a Design Responsible Engineer/Team as a means to assure potential failure modes, causes and effects have been addressed for design related characteristics
Process (PFMEA): technique used primarily by a Manufacturing Engineer/Team as a means to assure potential failure modes, causes and effects have been addressed for process related characteristics

11. The Pre-work Process or Prepared By ____________ Product Name _____
Page ________of ________
Person Responsible
__________________ FMEA Date (Orig.) _______ Revised _______

12. Guide to do FMEA STEP 1 STEP 2 STEP 3 STEP 4 STEP 5 STEP 6 STEP 7
Scope Project
STEP 2
Brainstorm all potential failures
STEP 3
Identify potential effects of failures
STEP 4
Determine severity rankings
STEP 5
Identify causes of failures
STEP 6
Determine occurrence rankings
STEP 7
Define current control methods
STEP 8
Determine detection rankings
STEP 9
Calculate Risk Priority Numbers
STEP 10
Prioritize corrective actions

13. FMEA Worksheet Function Failure mode Failure effect S Failure Cause O
Current Control D
RPN
Rec. Actions 1. 2.

14. Terms and Definitions Fault Failure Function/Process Examples –
1. Pencil Sharpener
2. Oil changing process
Fault: Inability to function in a desired manner, or operation in an undesired manner, regardless of cause.
Failure: A fault owing to breakage, wear out, compromised structural integrity, etc.
FMEA does not limit itself strictly to failures, but includes faults.
All failures are faults; not all faults are failures. Faults can be caused by actions that are not strictly failures.

15. Def. Cont… Failure Mode The way failure occurs
Can cause a failure mode in another item
Identify and list possible failure modes
Examples –
1. Frequently breaking the graphite
2. Wrong type of oil or No oil added
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 like complaints, scrap, rework, turn backs, reviews, etc.
Talk to internal and external customer.

16. Def. Cont… Failure Effect
Immediate consequence of a failure
Effects can range from very small to major disasters.
Examples –
Improper writing
Engine wear or Engine Failure

17. Def. Cont… Severity (SEV)
Worst consequence of a failure
How is it determined?
Standard scale from 1 (no danger) to 10 (very severe)
Prioritize the failures modes and their effects
You may need to involve your customer in allocating this number

18. Def. Cont… Failure Cause
Design weakness - How the failure could occur?
Listed in technical terms and are documented
Examples –
1. Improper mixture of Graphite and Clay
2. Misread oil chart or Hurrying
How the failure could occur, described in terms of something that can be corrected or controlled
There could be more than one cause for each failure
Experiments have to be conducted to determine causes – use technical problem solving

19. Def. Cont… Occurrence (O)
Probability of the cause occurring
Look for similar products or processes
Probability number scale from 1 (not likely) to 10 (inevitable)
Detailed development section of FMEA Process

20. Def. Cont… Current Controls
Current controls that prevent the failure cause (before causing effects)
Examples –
1. improve quality of graphite
2. No control or engine light
Systematic device/methods in place to prevent or detect failure modes or causes (before causing effecs)
Control consists of inspection, audits, training, etc.

21. Def. Cont… Detection (D)
Assessment of the likelihood that the current controls will detect failure cause or failure, before it reaches the customer.
Different techniques are used by an engineer
Identify the detection number ‘D’, ranging from 1 (easily detectable) to 10 (cannot detect)

22. Def. Cont… Risk Priority No (RPN)
RPN = S * O * D
Risk that has greatest concern can be identified
Failures are prioritized according to:
- Severity
- Occurrence
- Detection
Requires additional planning or action

23. Pareto Diagram

24. Recommended Actions and Results
Address potential failures that have a high RPN
Are any further actions required?
Assign new value for S, O and D, and calculate new RPN value
Update the FMEA as the design or process changes
After these actions have been taken, re-assess the severity, probability and detection and review the revised RPN’s.
Update the FMEA as the design or process changes, the assessment changes or new information becomes known, for e.g. customer feedback or customer reviews on a product or service.
FMEA must be a live document. Review regularly. Reassess rankings whenever changes made to product and/or process. Add any new defects or potential problems when found.

25. Development Team Crucial step in FMEA FMEA is a team function
- Formulate cross functional team
- Understand customer requirements – both internal and external inputs
- All team members walk and observe the process
- Make notes or observations

26. Link with continuous improvement
FMEA
Continuous Improvement Programs
Component Proving Process
Mistake Proofing
Techniques

27. FMEA Timing FMEA should be updated whenever: - At the conceptual stage
- Changes are made in the design
- New regulations are instituted
- Customer feedback indicates a problem

28. Uses of FMEA Development of methods to design
Test systems to ensure that the failures are eliminated
Tracking and managing potential risks
Ensuring that failure will not injure customer or impact a system
Evaluation of customer reviews on the problems indicated

29. TQM Principles Continuous Improvement Process
Continued building and prevention of failure on the process
Employee Involvement and Empowerment
Employees can feel empowered and involved if they correct an error in a process or part.
Leadership
There needs to be a team leader for every group, which is assigned to one part of the process.

30. TQM Principles Performance Measurement RPN, lower the better
Supplier Partnership
If one supplier has bad parts, it directly affects your products, by creating failure in your company.
End Customer Satisfaction
Reliability meets customer requirements 30

31. Limitations FMEA is limited by the team experience
FMEA may only identify and avoid major failure modes
Multiplication of rankings may result in rank reversals

32. FMEA Conclusion
Purpose of FMEA, is the process of identifying potential failure modes and their associated causes, assigning severity, Occurrence, and Detection ratings, and calculating RPN
RPNs should be used for continuous improvement activities

33. Resources