FMEA 1. Definition 2. Process FMEA 3. When to create FMEA

FMEA 1. Definition 2. Process FMEA 3. When to create FMEA
4. Preparation 5. Process FMEA Creation Procedure 6. Check List

1. Definition Ranking FMEA (Failure Mode and Effects Analysis)
System FMEA the highest level of FMEA done during the initial design phase of a system or subsystem Design FMEA used to identify and prevent failures associated with product design Process FMEA FMEA that identify and prevent failures associated with manufacturing or any other processes FMEA (Failure Mode and Effects Analysis) Failure mode and effects analysis a series of systematic activities leading to the next target find and analyze potential failures and effects of a product or process find a way to eliminate or reduce the occurrence of potential failure documentation of process

What is FMEA(Failure Mode and Effects Analysis)?
FMEA: find the potential failure modes of designed system or apparatus, and when such failure occurs during the operation of a system or apparatus, investigate and evaluate its effect to the performance, and prevent the occurrence of a failure in advance applying proper measures of correction to the failure mode that has big effects.

History of FMEA  early 1950s: propeller airplane  Jet airplane (reliability design of Jets that has complicated control systems)  mid 1960s: introduced to Aero-Space industry (Apollo) (big achievement in reliability warranty and safety assessment)  1974: used in U.S. Navy (MILSTD1629) late 1970s: wide-spread due to the introduction of Product Liability

Where do Risks come from?
Imperfect control plan Potential safety risk Uncertain customer needs Insufficient process capability Cumulative Risks Unclear operation standard Material variation Machine reliability Imperfect standard limits Measurement variation

Defects - Types -  out-of-normal during manufacturing process
 defects during design stage  out-of-normal during manufacturing process  unsatisfied performance that can not meet customer needs  dangerous state due to the lack of proper warning and training - Cause of Defects -  Design Defects - affects the whole line  Manufacturing Defects - Defects from raw material - Production mistake  Service Defects - can’t meet the standards defined by the design and the customers - Types -

Benefits of FMEA • Improve product quality, reliability, and safety
• Improve company image and competition • Increase customer satisfaction • Reduce product development time and cost • Reduce risks with documentation

Application of FMEA System FMEA : Design FMEA : Process FMEA :
• applied to the analysis of system/subsystem during product planning and design stage in early development • focus: potential failure mode associated with system function Design FMEA : • before production, applied to product analysis • focus : product function Process FMEA : • applied to the analysis of manufacturing and assembly • focus : process input variable Big 3 (Chrysler,Ford, GM) QS 9000

2. Process FMEA  Usage  Contents
 Identifies failures from products or process due to X.  Facilitates the documentation of a plan to prevent these failures.  Used as a basic information from which a list of items for the control plan can be generated.  Used to track necessary treatment to improve processes and identify priorities.  Contents  A detailed document which identifies ways in which a process or product fails to meet critical customer requirements (Ys).  A living document which lists all possible causes of failure (X)  Ultimately captures the entire process

Purpose of Process FMEA
• Helps to analyze new manufacturing process • Can identify defects of process control plan • Determine priorities of actions • risk analysis from process change • identify potential variables considered later • allows process design engineers understand current processes’ weak points and guides them to develop new manufacturing processes • steps for leaping

Process Improvement Plan
Process Map C & E Matrix output 문서 작업 DICY 탱크 steam DMF 장착 DICY 장착  장착정확성 ↑청결 ↑원료 재료목록 ISO 진행 재생 척도정확성  예열 Gel 시간 점 도 장착정확성 ↑환경 ↑원료  혼합속도 색 상 input FMEA Initial evaluation of process capability and control plan 잠재적 고장 영향 치 명 도 공정 단계 / 입력 잠재적 고장모드 감 지 도 관 리 발생 빈도 원 인 RPN 공 정 단 계 주요 공정 입력 Failure Modes -잘 못 될 수 있는 것 Effects Cause Current Controls

Input and Output Elements of FMEA
• Process Map • C & E Matrix • Risk Analysis • Process History • action statement to find out failures, identify causes, and prevent failures • record solutions

3. When to create FMEA  General Points Design FMEA Process FMEA
 System FMEA - after system functions are defined - before specific H/W is selected Design FMEA - after product function is defined - before design is approved Process FMEA - when preliminary product drawing is complete and related process flow is developed  General Points - design new system, product, and process, or new technology is introduced - when an existing design or process is changed - when applied to a new application or environment

FMEA Execution Table Comments) Since FMEA is a Living Document, its completion means that it becomes the basis for the input to the next level. It never means it is finished.

4. Preparation Who: Confirmation of purpose
product quality, reliability, safety improvement setup analysis and test method for the intended design risk analysis and reduced warranty cost evaluation of product design documentation of past experience increased customer satisfaction reduced product development time and cost Who: project team person who has a role in defining, executing, or changing process operators maintenance technicians engineers supervisors managers design engineers etc.

Collect necessary info.
past documentation of similar product or process A/S data of similar products design standard and parameter check list guide, rules related technology advancement status check test results analysis customer requirements specification list of basic functions predicted environment and conditions for use government and safety regulations related standards Preparation for proper block diagram System FMEA hierarchical block diagram create a tree diagram of subsystem that makes up for product, assembly, module, parts, and components function block diagram shows flow relations between components for successful operation of product reliability block diagram shows dependence or independence relations in terms of reliability Process FMEA Process map C&E matrix

FMEA Definitions  System : combination of subsystems that has all functions to accomplish required duty  Subsystem : a portion of a system, where it shares the system’s role and accomplishes the functions of the system

 Component : represents functional and assembly part that form system or subsystem  functional part : a few to hundreds of parts joined, and itself performs independent and general functions  assembly : 2 or more parts joined, and functions as a subsystem  part : an object which is not disassembled if not broken down. Has a given characteristics by the design.

Formation of a System Functional Subsystem part Assembly Component

Important Terms of FMEA (1)
Failure Mode Effect • a process fails to perform its intended function. • If not found during processing, it will eventually give undesirable effect to the customer. - related to defects - process input variable that deviates from standard - Any matters that a operator determines as a failure mode • effect that reaches to the customer • target : - outside customer - following process

defects during manufacturing
 Types of a Failure Mode defects during design - defects that can be seen as inherent to the design principle - absent or missing engineering drawing defects during manufacturing - manufacturing defects - assembly mistake defects during quality control - insufficient inspection or mistake - improper process control defects during use - wrong operation - use under different pattern to the design condition defects during storage - mistake from storage - absent of storage manual

Important Terms of FMEA (2)
Cause Current Controls • failure mode and cause examination, and systematic method to prevent failure in advance • prevention : Fool Proof design Fail Safe design • control : audit, check list, inspection, lab test, training, prevention, etc. • origin of process change that causes failure mode • cause examination : give preference to the failure mode with highest fatality

FMEA Preparation Procedures
Define system function - confirm and define the system function which FMEA performed on Decision of decomposition level of the system -decision of decomposition level and degree of the system -decide up to which level it is considered as a component System Subsystem Subsystem Assembly Assembly Part Part Part Single part Single part Single part Single part

Block Diagram Generation
- Generation of functional block diagram of a ystem - method : following the operations of a system, link the part serially if the part fails the system also fails, link parts parallel if several parts fails the system fails. - two types 1. By function 2. Write out fatal failure, medium failure, light failure

Electric refrigerator
기능별 블록 다이어그램 예 Electric refrigerator Cooling function Control function Storage function Compressor Condenser Cooling Heat exchanger Compressor Condenser Cooling Compressor Condenser Cooling

FMEA Methodology : start with C&E Matrix
• Merit : C&E matrix helps problem definition - customer’s critical requirements - process input that gives potential effect to the customer requirements - assign priority to major process input variables that affect output variable C & E Matrix offers quantitative measures that can be used to determine the severity of FMEA

5. Process FMEA creation procedures
Step1. Basic item entry FMEA number tracking FMEA type analysis level applicable process process responsibility (department) prepared by name contact related product model name First target date initial FMEA duty completion date Origination date first origination date final correction date fill in all together team member list all team member’s name contact

Step 2. List process functions
- list process function clear and short (noun + verb) - list separately if several functions occurrence ranking detection # process step potential failure mode potential effect severity R P N Potential cause Current process control status (process function) (process defects) Load bracket1 and housing into fixture

Step 3. List potential failure mode
occurrence detection # process step potential failure mode potential effect severity ranking R P N Potential cause Current process control status (process function) (process defects) Load bracket1 and housing into fixture Unfit part size Inexact load List all potential failure modes (incorrect operation) that can occur under actual operation environment (temp, moisture, dust, vibration, etc)

material or process input outside customer, following process
FMEA Model Causes Failure modes (detection) Effects material or process input process step outside customer, following process Controls

Step 4. List potential effects
severity ranking occurrence detection # process step potential failure mode potential effect R P N Potential cause Current process control status (process function) (process defects) Load bracket1 and housing into fixture Unfit part size Process delayed Inexact load Unable to final assembly extent of effects recognized by internal or external customers. dangers that can affect safety or regulations, etc.

Relations between failure mode and effects
Failure mode and effect is not a 1 to 1 relations.

Step 5. List Severity Ranking
occurrence # process step potential failure mode potential effect severity ranking detection Current process control status R P N Potential cause (process function) (process defects) Load bracket1 and housing into fixture Unfit part size Process delay 2 Inexact load Unable to final assembly 8 severity ranking of potential effects each failure mode has only one severity ranking (the most severe effects)

Severity Ranking Guidelines
10 points Hazardous without warning conflict with safety or government regulations without warning 9 points Hazardous with warning conflict with safety or government regulations with warning 8 points Very High major disruption to product line 7 points High minor disruption to product line customer dissatisfied 6 points Moderate convenience item(s) inoperable 5 points Low convenience item(s) operable at reduced level of performance 4 points Very Low Defect seen by most customers 3 points Minor finish defect noticed by average customers 2 points Very Minor finish defect noticed by discriminating customers 1 points None

Step 6. List potential cause and failure mechanism
ranking occurrence # process step potential failure mode potential effect severity detection Potential cause Current process control status R P N (process function) (process defects) Incoming part dim out of print Load bracket1 and housing into fixture Unfit part size Process delay 2 3 Unable to final assembly Operator error 5 Inexact load 8 weakness point list all possible causes of potential failure mode. Through repeated what? and why? Questions, list fundamental causes In order to find fundamental causes, can use cause and effect diagram or FTA.

Used to classify special product characteristics
Step 7. List rankings Used to classify special product characteristics characteristics necessary for additional process control. characteristics that affect safety. characteristics specified in government regulations. Reversed triangle representation used for characteristics whose severity is greater than 8. possible to use for characteristics whose severity is between 4 and 8 Usage and Fill-in to reflect company standards or procedures first list severity ranking and failure cause then filled in by the FMEA leader

Step 8. Occurrence Ranking Guidelines
5 points 1 in 400 occasional failures 4 points 1 in 2,000 3 points 1 in 15,000 relatively low failures 2 points 1 in150,000 1 points  1 in 1,500,000 unlikely failures 10 points  1 in 2 failure is almost inevitable 9 points 1 in 3 8 points 1 in 8 repeated failures 7 points 1 in 20 6 points 1 in 80

Step 9. List current process control status
occurrence # process step potential failure mode potential effect severity ranking Current process control status detection R P N Potential cause (process function) (process defects) Load bracket1 and housing into fixture Incoming part dim out of print 3 Unfit part size Process delay 2 Receiving inspection 6 Unable to final assembly 100% visual inspection Operator error 5 4 Inexact load 8 current control items to eliminate causes of potential failure modes preventive items find causes for corrections find failure mode itself

Step 10. Detection Ranking Guidelines
5 points Moderate average possibility to detect causes and related failures with current controls 4 points Moderately High above average possibility to detect causes and related failures with current controls 3 points High high possibility to detect causes and related failures with current controls 2 points Very High very high possibility to detect causes and related failures with current controls 1 points Almost Certain sure to detect causes and related failures with current controls 10 points Absolute Uncertainty unable to detect causes and related failures with current controls 9 points Very Remote very unlikely to detect causes and related failures with current controls 8 points Remote unlikely to detect causes and related failures with current controls 7 points Very Low low possibility to detect causes and related failures with current controls 6 points Low

Material or process input
FMEA Model Causes prevention detection Failure Mode (Analyze) detection Effects detection Material or process input process step Outside customer, following process Which is an optimal status? Control

Step 11. Fill in RPN Step 12. Take action RPN = severity ranking
* occurrence ranking * detection ranking focus on failure mode with the highest RPN For failure mode with a not so high RPN, but with high severity, pay special attention. Step 12. Take action very important to finish this part, track, and confirm detection ranking improvement through process confirmation and verification occurrence ranking Improvement through process change severity ranking improvement through process change and failure mode elimination.

Risk Priority Number • RPN : outcome from FMEA • RPN calculation:
• potential failure mode • effect of failure mode • possible to find failure mode before a product is delivered to the customer.

RPN = Severity * Occurrence * Detection
RPN Calculation RPN = Severity * Occurrence * Detection Effects Causes Controls • possible to add other items • RPN doesn’t have a value inherent to product category.

RPN Ranking Example

Step 14. Actual action date - items acted upon actually
Step 15. RPN recalculation - severity - occurrence - detection find RPN after recalculating it . Step 13. Assign responsibility - responsible person . contact . department - expected completion date occurrence detection R P N Recommended actions Person and target date severity Applied actions Need statistical tools BB 2000/1/15 Attribute Sampling single sampling inspection Fill in numbers changed after recommend actions have been take.

Quiz! • Complete the following table : 5 minutes
• Discuss about the results : 10 minutes

Quiz! (Results) optimal status no action guaranteed control no action
failure not reaching the customer no action failure reaching the customer action frequent failure, detection, cost action frequent failure, reaching the customer action Main effect from frequent failure action Big problem action

Taking Actions against RPN Value
• Necessary to establish improvement actions if RPN is greater than 100 or Ranking of Failure Occurrence, Severity, or Detection is greater than 8 • Mark star (*) in the applicable items in FMEA • If it is not necessary to plan improvement actions, mark NOR (Not Requirement) in the applicable item.

6. Process FMEA Check List
Failure Mode does it explain why this failure mode results in parts being out of specification? Did you list the part characteristics which resulted from failure mode? Are inspection and test related items included in failure modes?? Defective part received Qualified parts rejected If failure mode passes bad effects to the following process, Is the failure mode identified as the cause of the following operation? Is the failure of the following operation identified? Preparation FMEA team formed? Background information confirmed? Process Map Process map generated? Ys for each process step listed? Xs for each process step listed? Fundamental items fundamental items filled in? Fill in function each operation’s function listed clearly?

Current control status Is it ready to detect defectives?
Effect of Failure Is it considered the dangerous effects of machine, operator, and final customers? Are the effects of the following lines listed? Later operation next user and final customer transport method government regulations Cause of Failure/ Mechanism Is there a confirmation of the possible failures in the process? Is it presented as features requiring correction or control? Are process characteristics considered? Is there a consideration for design weakness? Are materials and subparts for each operation considered? Is there a consideration for the operators’ work? Current control status Is it ready to detect defectives? Can it detect defectives before the completion of operation? Can you tell whether it is for detection or prevention? Severity Ranking Is it sorted according to the highest severity effects of failure mode? Does it conflict to extent of the effect to customers? Occurrence Ranking Is it ranked, considering preventive control? Detect Ranking Is it determined based on the possibility that the current control can detect it before the completion of the operation?

Warning Is the action to reduce fatal defects of the main characteristics considered? Is special control to the main characteristics considered? Are all main characteristics considered? Is treatment action related to the failure mode that has the highest RPN? Are persons responsible for the warning treatment and the time limit specified? Is preventive action considered first? Is action to eliminate or reduce the occurrence of dangerous failure mode considered? Ranking Classification Is it confirmed the main characteristics and its special control? Are the main characteristics represented by the reversed triangle? Are the main characteristics understood as process or part characteristics? Are the main characteristics and its special control notified to the design manager? RPN Is RPN sorted according to the highest order?

FMEA (Example) - 1 Following FMEA procedures ...
Main process input variable : scale accuracy, steam heat DICY tank Process step Main process input Failure mode Effect Cause Control Steam heat DICY tank scale accuracy

FMEA (Example) - 2 process input variable Process Main process Failure
• Input failure mode based on the main process input variable Process step Main process input Failure mode Effect Cause Control Steam heat DICY tank scale accuracy scale > 0 scale inaccuracy scale out of zero setting

• List effects due to failure mode
FMEA (Example) - 3 • List effects due to failure mode Process step Main process input Failure mode Effect Cause Control Steam heat DICY tank scale accuracy scale > 0 low DMF recharge scale inaccuracy high DMF recharge scale out of zero setting wrong DMF recharge

• List cause of the failure mode
FMEA (Example) - 4 • List cause of the failure mode Process step Main process input Failure mode Effect Cause Control Steam heat DICY tank scale accuracy scale > 0 low DMF recharge water in Jacket scale inaccuracy high DMF recharge Tank delay scale out of zero setting wrong DMF recharge unstable scale

• List current control methods to each cause
FMEA (Example) - 5 • List current control methods to each cause Process step Main process input Failure mode Effect Cause Control Steam heat DICY tank scale accuracy scale > 0 low DMF recharge water in Jacket Jacket: Visual check(SOP 5681) scale inaccuracy high DMF recharge Tank delay Visual check (SOP 5681) scale out of zero setting wrong DMF recharge unstable scale None FMEA confirms initial defects in control.

FMEA (Example) - 6 Process step Main process input Failure mode Effect
Cause Control Steam heat DICY tank scale accuracy scale > 0 low DMF recharge water in Jacket Jacket: Visual check(SOP 5681) scale inaccuracy high DMF recharge Tank delay Visual check (SOP 5681) scale out of zero setting wrong DMF recharge unstable scale None DMF installation accurately DMF installation wrong DMF recharge

Cause Control Steam heat DICY tank scale accuracy scale > 0 low DMF recharge water in Jacket Jacket: Visual check(SOP 5681) scale inaccuracy high DMF recharge Tank delay Visual check (SOP 5681) scale out of zero setting wrong DMF recharge unstable scale None DMF installation accurately DMF installation wrong DMF recharge Extent to out of print

Cause Control Steam heat DICY tank scale accuracy scale > 0 low DMF recharge water in Jacket Jacket: Visual check(SOP 5681) scale inaccuracy high DMF recharge Tank delay Visual check (SOP 5681) scale out of zero setting wrong DMF recharge unstable scale None DMF installation accurately DMF installation wrong DMF recharge Extent to out of print Broken apparatus Out of SOP standards

Operator certificate/
FMEA (Example) - 9 Process step Main process input Failure mode Effect Cause Control Steam heat DICY tank scale accuracy scale > 0 low DMF recharge water in Jacket Jacket: Visual check(SOP 5681) scale inaccuracy high DMF recharge Tank delay Visual check (SOP 5681) scale out of zero setting wrong DMF recharge unstable scale None DMF installation accurately DMF installation wrong DMF recharge Maintenance repair procedure (SOP 5821)/ visual check Extent to out of print Broken apparatus Out of SOP standards Operator certificate/ process audit

FMEA (Example) - 10_1 • assign ranking to each severity, occurrence, and detection • RPN calculation Process steps/ input Failure mode Effect severity Cause Occur- rence control Detec- tion RPN Steam heat DICY tank/ scale accuracy scale > 0 low DMF charge 3 Water in Jacket 2 Jacket: visual check (SOP 5681) 1 6 Scale inaccuracy High DFM charge 3 Tank delay 2 Visual check (SOP 5681) 3 18 Scale out of zero setting wrong DMF charge 3 Unstable scale 2 None 9 54 DMF charge/ DMF accurate installation wrong DMF charge Extent to out of print Broken apparatus 2 Maintenance repair procedure (SOP 5821)/ visual check 7 3 42 7 Out of SOP standard 5 Operator certificate/ process audit 5 175

FMEA (Example) - 10_2 • sort by RPN Process steps/ input Failure mode Effect severity Cause Occur- rence control Detec- tion RPN DMF charge/ DMF accurate installation wrong DMF charge Extent to out of print 7 Out of SOP standard 5 Operator certificate/ process audit 5 175 Steam heat DICY tank/ scale accuracy Scale out of zero setting wrong DMF charge 3 Unstable scale 2 None 9 54 DMF charge/ DMF accurate installation wrong DMF charge Extent to out of print Maintenance repair procedure (SOP 5821)/ visual check 7 Broken apparatus 2 3 42 Steam heat DICY tank/ scale accuracy Scale inaccuracy High DFM charge 3 Tank delay 2 Visual check (SOP 5681) 3 18 Steam heat DICY tank/ scale accuracy scale > 0 low DMF charge 3 Water in Jacket 2 Jacket: visual check (SOP 5681) 1 6

• decide necessary action (only for higher RPN) Operator certificate/
FMEA (Example) - 11 • decide necessary action (only for higher RPN) Process steps/ input Failure mode Effect severity Cause Occur- rence Detec- tion Necessary action control RPN DMF charge/ DMF accurate installation wrong DMF charge Extent to out of print 7 Out of SOP standard 5 Operator certificate/ process audit 5 175 Full proof design Steam heat DICY tank/ scale accuracy Scale out of zero setting wrong DMF charge 3 Unstable scale 2 None 9 54 Daily checkup scale function DMF charge/ DMF accurate installation wrong DMF charge Extent to out of print Maintenance repair procedure (SOP 5821)/ visual check 7 Broken apparatus 2 3 42 Steam heat DICY tank/ scale accuracy Scale inaccuracy High DFM charge Visual check (SOP 5681) 3 Tank delay 2 3 18 Steam heat DICY tank/ scale accuracy scale > 0 low DMF charge 3 Water in Jacket 2 Jacket: visual check (SOP 5681) 1 6

FMEA (Example) - 12 • proper action and documentation • RPN recalculation Occur- rence Detec- tion Occur- rence Detec- tion cause control RPN severity Necessary action Resp. Action taken RPN Out of SOP standard automatic DMF recharger 8/96 Operator certificate/ process audit Full proof design 5 SZ 5 175 7 1 2 14 Unstable scale Daily checkup scale function 2 None 9 54 PQ Broken apparatus Maintenance repair procedure (SOP 5821)/ visual check 2 3 42 Tank delay Visual check (SOP 5681) 2 3 18 Water in Jacket Jacket: visual check (SOP 5681) 2 1 6

FMEA Approach Method 1 : Focus of C & E Matrix
- Start with the main input factor with the highest point in C & E Matrix analysis - Fill in the worksheet the above input factors. - Calculate RPN, then develop control methods for the failure mode with the highest RPN. - Complete process FMEA for all other input factors. Method 2 : Focus of FMEA itself - Fill in the worksheet failure mode and effects. - List causes of failure mode with the highest Severity ranking, and evaluate possibility of occurrence. - Evaluate current control status for high value of (severity X occurrence). - Develop control methods for the item with the highest RPN.

Method 3: Total Approach
- Good approach for small processes. - List in the worksheet from start process to finish process. - Calculate severity, occurrence, and detection ranking for all causes. - Develop control methods for the item with the highest RPN. Method 4: Super Focused - Generate Pareto chart and sort out main defects items or failure modes. - FMEA focuses on defects or failure modes. - Purpose : disappearance of failure modes

Catapult Device Ball type Hook position Pin position Golf ball
1 2 Ball type 1 1 Hook position 2 2 Pin position 3 Golf ball 4 Stop position 3 2 4 Throwing angle Number of rubber bands (1 - 3) 1 5 Table tennis ball 6

FMEA 1. Definition 2. Process FMEA 3. When to create FMEA

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FMEA 1. Definition 2. Process FMEA 3. When to create FMEA

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