21. 先決條件: 活動開始前…
流程已經被定義
產品的關鍵特性已經被定義
PFMEA成員已經決定
活動
列出主要的製程步驟
鑑別每一步驟/製程的關鍵功能
範例
PFMEA – STEP 1: 檢視製程
Step # Process Function/Requirements
1. Load Conveyor Transfer the cell stack magazine to unload position for Step#2
2. PnP Robot#1 Pick and place cell stack
3. Datum Station Datum cell stack
4. PnP Robot#2 Pick and place inside laminated package
5. Folding Station Fold over the pouch
6. Top Seal Station Seal top edge
7. Side Seal Station Seal side edge
Cell Packaging
Workstation
22. 先決條件: 活動開始前…
流程的功能已經被定義
活動
針對每一個功能, 團隊以腦力激盪的方式, 同時參考
以下的數種類型失效類型, 找出功能會如何失效:
• 完全沒功能
• 部分沒功能
• 功能較差
• 功能延遲出現
• 間歇性失效
範例
PFMEA – STEP 2:找出關鍵功能的失效模式
Process Function/Requirements Potential Failure Mode
Transfer the cell stack magazine to
unload position for Step#2
Conveyor fails to start when loaded
Conveyor jams midway
Conveyor completes transfer but triggers an alarm
Conveyor intermittently transfers to position
Conveyor takes too long to transfer
23. 先決條件: 活動開始前…
失效模式已經被定義
活動
針對每個失效模式, 找出對於下列對象會有怎樣的失效效應:
• 產品的表現
• 下游的製程/設備
• 內部客戶
• 外部客戶
範例
PFMEA – STEP 3:列出潛在失效效應
Potential Failure Mode Potential Effect(s) of Failure
Conveyor fails to start when loaded Line down, requiring reset/reloading
Conveyor jams midway
1. Damages cell stacks
2. Creates trip hazard for Operator
Conveyor completes transfer but triggers
an alarm
Interrupts line operation until fault is cleared
Conveyor intermittently transfers to
position
Frequent maintenance
Conveyor takes too long to transfer Reduces throughput
24. 先決條件: 活動開始前…
失效效應已經被定義
活動
考慮各個失效效應的嚴重度並且排名, 與安全及法規有關的一定得分最高
標註Class欄位:
為了鑑別降低風險措施的控制參數, 使用Class此欄位來標註高嚴重度的失效模式
範例
PFMEA – STEP 4:給予嚴重度評分
Potential Effect(s) of
Failure Sev Class
Line down, requiring
reset/reloading
7
1. Damages cell stacks 7
2. Creates trip hazard for
Operator
9
C
Interrupts line operation
until fault is cleared
6
Frequent maintenance 7
Reduces throughput 7
25. 先決條件: 活動開始前…
失效模式已經被定義
活動
針對每個失效模式, 找出任何可能發生的原因! 故障樹或類似的分析可以應用於達成此步驟
• 注意: 此一步驟並非要找出真因; 在下一步驟中, 發生度的評分才有可能指向真正發生的原因
範例
PFMEA – STEP 5:鑑別失效的可能原因/機制
Potential Failure Mode Potential Effect(s) of Failure Sev Class Potential Cause(s) / Mechanism(s) of Failure
Conveyor fails to start when loaded Line down, requiring reset/reloading 7
Faulty sensor (start position)
Faulty belt
Conveyor jams midway
1. Damages cell stacks 7
1. Lose bolt trapped within the conveyor
2. Worn-out Conveyor links
2. Creates trip hazard for Operator 9
1. Lose bolt trapped within the conveyor
2. Worn-out Conveyor links
Conveyor completes transfer but triggers an
alarm
Interrupts line operation until fault is cleared 6
Faulty sensor (end position)
Faulty belt
Conveyor intermittently transfers to position Frequent maintenance 7
1. Worn-out conveyor links
2. Debris on the conveyor
Conveyor takes too long to transfer Reduces throughput 7
Conveyor speed programming error
Incorrect conveyor/motor selection
35. 準備工作: 流程表
Process
Identification
Process Instruction Sources of Variation Existing Control
100.40.10
Install Elbow Fitting to Valve.
Tighten with wrenches.
Incorrect orientation
Quality check - Second person
verify
Not securely tightened
100.40.20
Verify correct flow direction.
Install valve to middle of left
side bracket. Secure Hand
Tight to bracket with
hardware.
Incorrect flow direction
Quality check - Second person
verify
incorrect location on bracket
installed to incorrect bracket
insufficiently tightened
100.40.30
Label valve “V82C” using
frestock label sheet 785-
222578-001
Incorrect Label used (V82B)
Incorrect orientation of label on
valve
41. Severity (S)
嚴重度
Ranking
Level of
Severity
Process Impact
Generic Manufacturing
1 No Impact No Impact
- No discernable effect
- No Non-conformance recorded
2 Very Minor
- Minor Disruption with rework/adjustment/correction at the process
step (i.e. same workstation, cubicle, desk, etc…)
- Slows down process progress
- Annoyance or squeak/rattle
- Visual defects which do not affect function
- Minor disruption to manufacturing line
- Slight inconvenience to process, operation, or assembler
- Non-conformance recorded but decision for affected part(s) is to "Use as is"
3 Minor
- Minor disruption to the manufacturing line
- Slight inconvenience to process, operation or assembler
- Non-conformance recorded and need to obtain a part (i.e. missing part)
4 Very Low
- Minor disruption to the manufacturing line
- Moderate inconvenience to process, operation or assembler
- Non-conformance recorded for rework
- Affected parts are low cost
5 Low
- Moderate disruption with rework out of the process step (i.e. different
workstation, cubicle, desk, etc…)
- Additional operations required
- Moderate disruption to the manufacturing line
- Moderate inconvenience to process, operation or assembler
- Non-conformance recorded for rework
- Affected parts are lower cost
6 Moderate
- Moderate disruption to the manufacturing line
- Moderate inconvenience to process, operation or assembler
- Non-conformance recorded for removal
- Affected parts are higher cost
- Issue causes decreased line speed or added manpower
7 High - Major disruption, rework and/or scrap is produced
- May shutdown process at customer or internally within the
organization
- Major disruption to the manufacturing line.
- Major inconvenience to process, operation or assembler
- Non-conformance recorded for removal
- Affected parts are higher cost
- Issues causes large reduction in line speed or large increase in added manpower
8 Very High
- Line shutdown or stop ship
- Non-conformance recorded
9
Hazardous
with Warning
Regulatory and safety of the station is a concern; unsafe work
conditions
- May endanger operator (machine or assembly) with warning.
- Failure mode affects safe operation and/or involves noncompliance with corporate safety practices
- Safety event recorded
- Production line down
10
Hazardous
without
Warning
- May endanger operator (machine or assembly) without warning.
- Failure mode affects safe operation and/or involves noncompliance with corporate safety practices
- Safety event recorded
- Evacuation needed
嚴重度, S, 由 1 到10, 來預估後果有多嚴重
43. 解釋發生度的評分
條列出現存可以預防失效原因發生的設計或程序 (包括制度面和方法面)
藉由這樣做, 可以使發生度的排名更明確
清楚的解釋可以提供更加得參考為未來FMEA的使用
Current Design Prevention Control & Explanation of Occurrence rating
現行的管制方式 & 發生度評分
44. Occurrence (O)
發生度
發生度的度量, O, 由1 到10 來估計失效的原因有多常發生?
Ranking
Likelihood of
Occurrence
Occurrence of Non-Conformances per Unit Time
Generic Manufacturing
1 Remote
- Prevented causes due to using a
known standard process.
- Prevented through Process
design/mistake proofing (Poke Yoke)
Zero (Eliminated through
preventive control)
2 Extremely Low once per quarter
3 Very Low
Isolated failures in the process
once per month
4 Low twice per month
5 Moderately Low Occasional failures have been
experienced
once per week
6 Moderate twice per week
7 Moderately High New process with no history (using
current processing
techniques/tools/equipment)
once per module
8 High twice per module
9 Very High New process with no history (using
NEW processing
techniques/tools/equipment)
once per shift
10 Extremely High twice per shift
46. Existing or implemented methods or actions to reduce or eliminate the risk associated with the
potential failure cause現存的或已導入的方法或措施來降低或消除與潛在失效原因相關的風險
管制措施可以作為預防或偵測
偵測面
1.相關的作業或檢驗指導書
2.管制圖
3.製程能力 (Ca、Cp、Cpk)
4.目視檢查
5.自主檢查
預防面
1.教育訓練
2.設備保養
3.防呆措施
單一失效原因可以有多個管制措施
Current Detection Design Controls & Explanation of detection rating
目前偵測設計&偵檢度評分
47. Detection (D)
偵檢度
Ranking Likelihood of Detection
Detection Capability
Generic Manufacturing
1 Almost Certain Cause has been fully prevented and cannot occur
- Detection not applicable
- All manufacturing errors are prevented with excellent process
controls in place
- All parts can be assembled as "poka-yoke"
2 Very High
- In process step (i.e. same
workstation, cubicle, desk, etc…), error detection will not allow defect to
be made.
- Automated defect detection
- Manufacturing error is detected during assembly step by an
automated system
- Manufacturing issue is prevented since error can be
immediately corrected at assembly step
3 High
- In process step (i.e. different workstation, cubicle, desk, etc…), failure
detection will not allow defect to pass/move on in process
- Automated defect detection
- Manufacturing error is detected after the assembly step is
completed by an automated system
- Assembly step is automatically stopped for further evaluation
when error is detected
4 Moderately High
- In the process step (i.e. same workstation, cubicle, desk, etc…), failure
detection will not allow defect to depart process step
- Manual defect detection (Control charts or other manual check system
is used to prevent defect from shipping)
- Manufacturing issue detected by manual methodology during
assembly step (i.e. Control charts or other manual check
system is used to prevent defect from shipping)
5 Moderate
- Out of the process step (i.e. different workstation, cubicle, desk, etc…),
failure detection will not allow defect to depart process step
- Manual defect detection (Control charts or other manual check system
is used to prevent defect from shipping)
- Manufacturing issue is detected by manual methodology after
assembly step has been completed (Control charts or other
manual check system is used to prevent failure from shipping)
6 Low
Visual inspection (Minor) In the process step (i.e. same workstation,
cubicle, desk, etc…)
- Manufacturing issue caught by visual inspection during
assembly step
7 Very Low
Visual inspection (Minor) Out of the process step (i.e. different
workstation, cubicle, desk, etc…)
- Manufacturing issue detected by visual inspection after
assembly step has completed
8 Remote Visual inspection (Major) at end of process flow - Manufacturing issue is detected at EOL final test
9 Very Remote
- Sample of product / In-depth inspection
- No controls but mitigation exists
- Not likely to detect by inspection at assembly step or at EOL
test
- No process control but a mitigation plan is in place
10 Almost Impossible No controls and no mitigation
- Impossible to detect manufacturing issue
- No available process control or mitigation plan in place
- Process must be fixed
偵檢度的度量, D, 由 1 到 10 來估計在檢測根因方面, 設計的敏感度有多高
53. PFMEA表
Created by Rev.
Date Created mm/dd/yyyy Last update
Recommended
Corrective Action(s)
Owner
Target
Completion
Date
Actions Taken
Severity(S)
Occurrence(O)
Detection(D)
RPN(S*O*D)
4000.30 - Water Valve Prep 7 1 5 35
9//10/18
10: Install one-touch fitting into 3-way valve. Fitting not threaded in all the way
Valve mulfunction
4
Insufficient training Human Workmanhip
standards/training/OMS
visuals
2 x
Can get dected
3 24 24
9//10/18
20: Wrap Teflon tape 3 times around threads of both 3/8" adapter fittings and install where
shown. Thread fittings completely into water valve so that no threads are exposed. Then
tighten an additional 1/2 turn. Fitting not installed correctly
Can leak
8
Insufficient training Human Training/OMS Visuals
5 x
Pressure decay and water leak test
3 120 120
9//10/18
30: Wrap Teflon tape 3 times around threads of the 3/8" connector fitting and install where
shown. Thread fitting completely into water valve so that no threads are exposed. Then
tighten an additional 1/2 turn. Fitting could leak if not installed correctly
Can leak
8
Insufficient training Human Teflon wrapping step could
be a source of varation 5 x
Pressure decay and water leak test
3 120 120
9//10/18
40: Install elbow fitting into previously installed 3/8" connector fitting. Hold 3/8" fitting with
a wrench to ensure it is not loosened while installing elbow. Verify connection with Go/No-
Go gauge. Fitting could leak if not installed correctly
Can leak
8
Insufficient training Human Training/OMS Visuals
3 x
go/no go, pressure decay, water leak test
3 72 72
9//10/18 50: Mount bracket to water valve with hardware and torque to 4 in-lbs. bracket loose Water valve not in place after shipping2 Incorrect torque/stripped thread Human Training/OMS Visuals 1 x oms instruction 9 18 18
9//10/18 Note: Repeat process on the second valve. x 0 0
9//10/18 4000.40 - Water Valve Assembly Install x 0 0
9//10/18
10: Orient and install water valves onto mezzanine shelf in the locations shown. Torque to
79 in-lbs. water valve lose in place Water valve not in place after shipping
2
incorrect torque
Human Training/OMS Visuals
1 x
oms instruction
9 18 18
9//10/18 20: Align the tee fittings as shown and secure with wrenches. Ensure previously installed
fittings are not loosened while installing Tee fittings. Verify with Go/No-Go gauge. Fitting could leak if not installed correctly
can leak
7
Insufficient training Human Leak category
5 x
go/no go, pressure decay, water leak test
3 105 105
9//10/18
30: Align the elbow fittings as shown and secure with wrenches. Ensure previously
installed fittings are not loosened while installing elbow fittings. Fitting could leak if not installed correctly
can leak
7
Insufficient training Human Leak category
5 x
go/no go, pressure decay, water leak test
3 105 105
9//10/18 40: Verify all fittings with Go/No-Go gauge. x 0 0
9//10/18 50: Apply WV1 Label from label sheet to outer water valve. Apply WV2 label to inner
water valve. w ater valve system not built to print
Leak
7 swapped labels could lead to
wrong connection
Method Labels can be
swapped/Previous Nce 5 x
OMS visual
8 280
Design Change
requested to reduce
occurrence
DPG Q1 2019 Proposal to DPG by MFG,
Benchmarking and cost
analysis in progress
7 1 8 56
9//10/18 4050.120 - Water Switch Pneumatic Bank x 0 0
9//10/18
10: Install pneumatic manifold to bracket using 4-40x.75 SKT Screws, #4 Lock and Small
OD Flat Washers. Torque to 5 in-lbs. Manifold lose in place
Manifold not in place securely
2
incorrectly torqued
Human Training/OMS Visuals
1 x
oms instruction
9 18 18
9//10/18
20: Using Label Maker create and apply A323 and A324 labels to pneumatic bank. Not built to print
Leak
7
Sw apping of connections Method Lables can be
swapped/Previous NCe 5 x
OMS visual
8 280
Process step added after NCE, labels could be swapped and lead to swapped connections. Design change requested to elimnate futre failure modes.
DPG Q1 2019 Proposal to DPG by MFG,
Benchmarking and cost
analysis in progress
7 1 8 56
9//10/18
30: Mount pneumatic manifold bracket and tie mounts to RF enclosure using 10-32x .5
BUT screws. Torque to 32 in-lbs. Brackets/Tie mounts not sceure
Manifold not in place securely
2
incorrectly torqued
Human Training/OMS Visuals
1 x
oms instruction
9 18 18
9//10/18 4150.20 - Lower RF Water Switch PFAs x 0 0
9//10/18
10: Cut and label PFAs according to table. Poly leaking Vlave not actuating
7
Incorrect length of PFA/ Slightly
angled cut that could cause failure
over-time
Method Length can be corrected by
rework but angled cuts
cannot be detected
5 x
polys cut too long, polys cut too short or angled would be caught in manufacturing
7 245
Design change
requested to
eliminate failure mode
DPG Q1 2019 Proposal to DPG by MFG,
Benchmarking and cost
analysis in progress
7 1 7 49
9//10/18 20: Connect A323 to WV1. Connection could be swapped Leak 7 Unclear labels Method Previous Nce 5 x 4 140 visual updated and leak check added after NCE. Test can catch this but we have still had escapesCompleted visual updated and leak check added after NCE. Test can catch this but we have still had escapes7 5 3 105
9//10/18 30: Connect A324 to WV2. Connection could be swapped Leak 7 Unclear labels Method Previous NCe 5 x visual updated and leak check added after NCE. Test can catch this but we have still had escapes4 140 visual updated and leak check added after NCE. Test can catch this but we have still had escapesCompleted visual updated and leak check added after NCE. Test can catch this but we have still had escapes7 5 3 105
9//10/18 40: Route both poly lines around the mezzanine to the pass-through. Coil poly near pass-
through. Lack of design for manufacturibility
Rew ork of process steps to
make sure routing of polys are
correct.
5
improper routing could make poly too short to connect
Method Training/OMS visuals
3 x
oms visual/ Can be detected in-process if too short to connect
3 45 45
Description Requirements Document
Occurrence(O)
Class
Current Process Controls & Explanation
of Detection Rating
Detection(D)
RPN(S*O*D)
mm/dd/yyyy
Post Action ScoresCorrective Actions
Nr.
Date
(started)
Process Function Potential Failure Mode
Title
Potential Effect(s) of
Failure
Severity(S)
Potential Cause(s) /
Mechanism(s) of Failure
Failure Category
Current Process Controls
& Explanation of
Occurence Rating
FMEA type_Product_ProcessStep