【Dell的FMEA教材失效模式影响分析】.docx

Failure Mode Effects Analysis
失效模式影响分析

Objectives
课程目标
By the end of the training, you will be able to:
在本堂课程结束时, 您将能够:

1. Compare and contrast the different types of failure mode effects analysis (FMEA).
比较与对照不同类别的失效模式影响分析 (FMEA).
2. Characterize the differences in questions asked in completing each type of FMEA.
区分在完成不同类别的FMEA过程中所提出问题的特性.
3. Define design FMEA and process FMEA.
定义设计FMEA与流程FMEA.
4. Describe how to apply FMEA to a process map.
了解如何将FMEA运用于流程图.
5. List the steps and components used in building an FMEA.
将建立FMEA的步骤与要件列出.
6. Demonstrate how to assess level of risk.
展示如何评估风险等级.
7. Prioritize risk assessment to drive corrective actions.
排定风险评估优先级以推动矫正措施.

FEMA and What is it?
什么是失效模式影响分析

FMEA

Could these have been avoided?
· The Bhopal tragedy
· The Valujet air crash
· The contamination of meat at Hudson Foods
· The Y2K problem

下列事件原本是否可以避免呢?
· 印度波布尔化工厂毒气外泄惨剧
· 美国Valujet 航空公司坠机意外
· 美国Hudson食品公司肉品污染事件
· 千禧虫问题

What is FMEA?
什么是失效模式影响分析
· Disciplined approach to studying failures in
- Product
- System
- Process
- Service
- Plus causes and effects
有系统的研究下列各种失效
- 产品
- 系统
- 流程
- 服务
- 原因与结果

· Method that quantifies level of risk
用量化评估风险等级的一种方法.
· Requirement of QS9000
QS9000 品管系统要求条件之一.
· Tool to use on new or existing products, processes, services, etc.
用于新的或现有的产品, 流程, 服务, 等等的工具.

When FMEA’s Should Be Conducted
何时该做FMEA

Life Cycle Cost
生命週期成本

Stages in Product/Service Life Cycle
產品/服務生命週期之各個階段

FMEA Exercise
FMEA练习

FMEA Exercise 1
FMEA练习一
Consider the pager as a communication device. Answer the following questions:
将呼叫器当做一个通讯工具. 回答下列问题:

1. Identify the most serious failure that can occur with a pager.
列出呼叫器可能发生最严重的失效状况 (故障).

_______________________________________________________________________________________________________________________________________________________________________________________

2. What could be the “worst case” effect of this failure?
这个失效状况所能导致的最糟结果是什么?

___________________________________________________________________________________________________________________________________________________________________________________________________________________________

3. Identify 5 causes that lead to such failure, and rank in order of priority for corrective action.
列出五个导致这个失效状况的原因, 并将它们矫正措施的优先等级列出.

Cause
原因
Rank
等级

FMEA Exercise 1, Continued
FMEA练习一, 续前页

Points to consider:
· What was the basis for allotting the ranks you did?
· How sure did you feel about what you were doing?
· Do you think your ranking will agree with most other people in the class? Why?
· Would a team effort be better or worse?
考虑以下各点:
· 您分配优先等级的参考依据是什么?
· 您对您的结论有多大的信心?
· 您认为这个班里大部份的学员会同意您的评比等级吗? 为什么?
· 小组合作的结果会更好或更差?

Failure Mode Effects Analysis, Continued
FMEA分析, 续前页

Probability of Occurrence – Cause
发生机率 –
原因
Very rare, maybe once in 10 yrs., or <1 ppb 1
非常罕见, 每＋年才可能发生一次, 或小于十亿分之一
Rare, maybe once in 5 yrs., or X00 ppb 2
罕见, 每五年才可能发生一次, 或大约为十亿分之数百
Could occur somewhat frequently, more than once / 2 yrs., or <100 ppm 3
发生频率略高于每两年一次, 或小于百万分之一百
Could occur 1 to 3 times / yr or between 100 and 1000 ppm 4
每年发生一至三次, 或介于百万分之一百至百万分之一干
Definitely more than one occurrence per quarter, or above 1000 ppm 5
发生频率多于每季一次, 或高于百万分之一千

Severity – Effect
严重性 –
影响
Minor inconvenience in personal / work life 1
对个人生活与工作稍有不便
Noticeable impact to work schedule / personal plans 2
对个人与工作计划稍有影响
Affects relationships with boss / family members 3
对上司 / 家人之间的关系有影响
Loss of revenue, relationships, and or reputation 4
对收入, 关系, 或名誉有损失
Could result in injury, / other safety issues 5
导致受伤或其它安全事故

Detection – Failure Mode (or Cause)
侦测能力 –
失效模式 (或原因)
Failure or its cause is readily or self evident 1
失效本身或其原因显而易见或自行彰显
Manual inspection or test can easily detect failure / cause 2
人工检验或测试可以轻易侦测到失效或其原因
Failure is hard to detect, special instruments or training req. 3
失效不易侦测, 必须要有特殊仪器或训练
Failure detection will destroy the unit 4
失效侦测过程会损毁产品
Failure can slip by unnoticed 5
无法侦测到失效

Complete the following FMEA Rating Worksheet for the problem in Exercise 1.
将练习一的问题排定FEMA优先等级并填入下表.

Product or feature
产品或特性
Failure mode
失效模式
Effect
影响
S
Cause
原因
O
Current controls
现行管制
D
RPN
风险系数
Rank
等级

Failure Mode Effects Analysis, Continued
FMEA分析, 续前页

Common types of FMEA
FMEA的一般类型
· Design/Product – Focus on product, system, sub-system, or component part
设计/产品 – 重点在产品, 系统, 次系统, 或零附件.
· Process – Focus process. Output usually a product
流程 – 重点在流程本身. 其输出通常为产品.
· Service – Focus on process, but output is service
服务 – 重点在流程. 但其输出为服务.

Design/Product FMEA
设计/产品FMEA
Benefits:
· Increases robustness of designs
· Identifies failure modes
· Enables priority setting for corrective action
· Supports failure discussion between different groups
· Provides a framework for continuous improvement of designs
· Identifies often missed failure modes when used at systems level

Customers: End user, manufacturing, assembly, service and …

好处:
· 更完善的产品设计
· 找出失效模式
· 得以设定矫正措施的优先级
· 支持不同工作小组之间的失效案例讨论
· 提供设计持续改善的工作架构
· 找出在系统阶层经常遗漏的失效模式

客户: 最终用户, 制造, 组装, 服务, 与…

Process FMEA
流程FMEA
Benefits:
· Increases robustness of process
· Identifies high risk process steps
· Identifies process variables controls
· Supports failure discussion between different groups
· Documents results of process
· Provides framework for continuous improvement of processes
· …
· …

Customers: End user, down stream manufacturing / assembly processes, service operations and…

好处:
· 更完善的流程设定
· 找出高风险的流程步骤
· 找出流程变量的控制办法
· 支持不同工作小组之间的失效案例讨论
· 经由纸上作业制订流程
· 提供流程持续改善的工作架构
· …
· …

客户: 最终用户, 下游制造, 组装流程, 服务作业, 与…

Failure Mode Effects Analysis, Continued
FMEA分析, 续前页

Service FMEA
服务FMEA
Benefits:
· Reduces probability of service not meeting expectations
· Identifies failure modes
· Enables prioritization for corrective action
· Pin points high risk steps in service process
· Identifies highest value control steps

Customers: End user, downstream process owners, and ….

好处:
· 降低服务不良的机率
· 找出失效模式
· 得以设定矫正措施的优先级
· 精确指出在服务流程中的高风险步骤
· 找出最高价值的管制步骤

客户: 最终用户, 下游流程负责人, 与…

Define the scope for the FMEA
定义FMEA的范围
Step 1
Define the boundaries within which the product, process, or service will be studied, identifying the operating assumptions, current conditions, and
Constraints’ if any.
步骤一
定义要所要研究的产品, 流程, 或服务的研究界限, 确定作业假设条件, 目前状况, 以及可能的限制.

The Influence of Level
不同阶层的影响
Radiator
Pump, V Belt

Diaphragm,
Bi Metal Spring

Safety, Lubrication
Engine, Braking, Exhaust
Trans., Cooling

Thermostat

Example of a Product

Level
阶层
Focus
重点
Failure Mode
失效模式
Cause
原因
Effect
影响
System
系统
Car
轿车
Overheating
引擎过热
Cooling system failure
冷却系统失效
Stranded on the road
在途中抛锚
Sub-system
次系统
Cooling system
冷却系统
Inadequate coolant flow
冷却剂循环不当
Thermostat stuck closed
澎胀阀死锁
Car overheating
轿车引擎过热
Sub-assembly
次组合
Thermostat
澎胀阀
Stuck closed
死锁
Bi-metal spring broken
铋金属弹簧断裂
Inadequate coolant flow
冷却剂循环不当
Component
零件
Bi-metal spring
铋金属弹簧
Broken
断裂
Fatigue
金属疲劳
Thermostat stuck closed
澎胀阀死锁

Failure Mode Effects Analysis, Continued
FMEA分析, 续前页

Example of a Process
流程举例

Company

Plant 4
Plant 3
Plant 2
Plant 1

PCB Line
Power supplies
FHP Motors

Op 250
Op 20
Op 10

FMEA can be conducted at any of these levels; it all depends on your objective
依据您的目的, FMEA可应用于以上任何一个阶层.
Op250
Op 240
210
Op 10
Op 120
Op250

OpA20
OpA10

Level
阶层
Focus
重点
Failure Mode
失效模式
Cause
原因
Effect
影响
System
系统
Factory (Plant 2)
工厂 (二厂)
Late delivers to customer
交货延迟
Low FPY on
Line 2
第二线直通率过低
Lost business
损失订单
Sub-system
次系统
Line 2
(power Supplies)
第二线 (电源供应器)
Low FPY
直通率过低
High rework at / after testing
测试后重工率太高
Late deliveries
交货延迟
Operation
作业站
Testing Op 210
第210测试站
High rework
重工率太高
Testing results inconsistent
测试结果不稳定
Low FPY
直通率过低
Important: You must be able to see a cascading of failure modes, causes, and effects.
重要提示: 您必需要能看出失效模式, 原因, 和影响的系列关联.
Failure Mode Effects Analysis, Continued
FMEA分析, 续前页

Define the scope for the FMEA, cont.
定义FMEA的范围, 续前页
Step 2
Identify team members, customer, and knowledge expert/s
Involve the customer in the process.
步骤二
确定小组成员, 客户, 与专家.
邀请客户参与作业

Step 3
Develop roles and responsibilities for team members
Leverage the strengths of each team member
步骤三
指派小组成员职掌
充分运用各小组成员之长处

Step 4
Study the product / Process / Service
All team members work to familiarize themselves with the product, process,
or service
步骤四
研究产品 / 流程 / 服务
各小组成员致力于熟习产品, 流程, 或服务

Step 5
Develop rating scales for Severity, Occurrence, and Detection
步骤五
建立严重性, 发生机率, 与侦测能力的评比等级

Quantifying failure modes, effects and causes
量化失效模式, 影响, 与原因
Causes Failure Modes* Effects
原因 失效模式 影響

Occurrence Detection Severity
發生機率 偵測能力 嚴重性

How severe?
有多嚴重?
Who has the most info?
誰有較多的資訊?
How easy to detect with current controls?
現有的偵測能力有多好?
Who has the most info?
誰有較多的資訊?
If prevented will effects be eliminated?
預防措施是否可以消除影響?

How frequent?
多頻繁?
Who has the most info?
誰有較多的資訊?
If eliminated, will failure be avoided?
如果消除了發生機率, 失效是否可以避免?

Failure Mode Effects AnalysisError! No text of specified style in document., Rating Scales
FMEA分析, 评比等级
来源于 中国最大的资料库下载

Rating scales
评比等级
Example from Design FMEA
设计FMEA举例

Severity 严重性
Occurrence 发生机率
Detection 侦测能力
Effect 影响
Cause 原因
Failure mode or cause 失效模式或原因
1 - No effect
无影响
2 - Minor effect - fit/cosmetics
轻微影响 – 配合 / 外观
3 - Major effect - fit/cosmetics
严重影响– 配合 / 外观
4 - Minor reduction in Function
功能稍受影响
5 - Customer dissatisfied
客户不满意
6 - Major reduction in function
功能大受影响
7 - Totally dysfunctional
功能完全不正常
8 - Presents minor hazard
形成轻微危险
9 - Presents injury hazard
造成受伤危险
10 - Fatal if used
造成致命危险
1 - Remote chance, <1ppm
微乎其微
2 - Very low 1-5
非常低
3 - Very low 5-10
非常低
4 - Moderate 10-100
中等程度
5 - Moderate 100-1K
中等程度
6 - High 1K-10K
高度
7 - High 10K-100K
高度
8 - Very High 100K-1M
非常高
9 - Very High 1M - 10M
非常高
10 - Almost certain
几乎是必然会发生
1 - Certain to be detected
一定能侦测出
2 - Very high chance of detection
非常高的机会能侦测出
3 - high chance of detection
很高的机会能侦测出
4 - Moderately high chance of detection
中高程度的机会能侦测出
5 - Moderate chance of detection
中等程度的机会能侦测出
6 - Low chance of detection
低程度的机会能侦测出
7 - Very low chance of detection
非常低程度的机会能侦测出
8 - Remote chance of detection
微乎其微的机会能侦测出
9 - Very remote chance of detection
非常微乎其微的机会能侦测出
10 - Slips by undetected
无法侦测

Rating scales
评比等级

FMEA; Step by Step
FMEA; 逐步展開
5 Develop rating scales for Severity, Occurrence,and Detection
Example from Process FMEA:

Severity - effect
1 – No effect on operators, users, or current and down stream processes
2 – Minor rework at current step / no dysfunction introduced in product
3 – Rework at current / subsequent steps causing some delayed schedules, or product is rendered partially dysfunctional
4 – Heavy rework at subsequent operation, major delays in schedules, or product function is severely impacted
5 – Risk of injury or fatal
Occurrence - cause
1 – Very rare occurrence, X00 ppb or once in 3 to 5 years
2 – Rare occurrence, X to X000 ppm, 2 to 5 occurrences in 3 years
3 – Frequent occurrence, X000 to X0,000 ppm, 1 to 3 occurrences in 1 year
4 – High frequency of occurrence, X0,000 to XM ppm, over 4 occurrences per year
5 – Almost certain
Detection – failure mode (or cause in some cases)
1 – Certain to be detected, before any measurable damage is done
2 – Automated inspection / detection or strong process controls exist at current step or within the system boundaries
3 – Sampling plans used for inspection purposes
4 – 100% manual inspection methods used within system boundaries
5 – Defect unlikely to be detected, will slip by unnoticed

5 建立嚴重性, 發生機率, 與偵測能力的評比等級
流程FMEA舉例:

嚴重性 – 影響
1. 對作業員, 使用者, 或目前及下游作業無影響.
2. 對該作業步驟輕微重工, 產品功能不受影響.
3. 對該作業 / 後續作業步驟重工而造成進度稍為落後, 或產品功能部份受影響.
4. 對後續作業步驟施以重大重工, 造成進度嚴重落後, 或產品功能嚴重受影響.
5. 有受傷或致命危險.
發生機率 – 原因
1. 發生機率非常罕見. 十億分之數百, 或三至五年發生一次.
2. 發生機率罕見. 百萬分之一至百萬分之數千, 或三年發生二至五次.
3. 發生機率時常. 百萬分之數千至百萬分之數萬, 或一年發生一至三次.
4. 發生機率頻繁. 百萬分之數萬至百萬分之數百萬, 或一年發生多於四次
5. 幾乎是必然會發生.
偵測能力 – 失效模式 (在某些案例中這個項目是原因)
1. 在損失造成前一定可以偵測到.
2. 自動檢驗 / 測試, 或對該流程或系統有週密的流程管制.
3. 依抽樣計劃檢驗.
4. 系統範圍內施行百分之百人工檢驗.
5. 無法偵測.

Failure Mode Effects Analysis, Continued
FMEA分析, 续前页

Rating Scale Worksheet
评比等级工作表

Severity
严重性
Occurrence
发生机率
Detection
侦测能力
Effect
影响
Cause
原因
Failure Mode or Cause
失效模式或原因

Failure Mode Effects Analysis, Continued
FMEA分析, 续前页

Define the scope for the FMEA, cont.
定义FMEA的范围, 续前页
Step 6
Brainstorm failure modes, known and potential
Identify as many failure modes as possible.
步骤六
运用脑力激荡方法找出已知和可能的失效模式
尽可能的找出各种失效模式
Separating Failure Modes, Effects and Causes
區分失效模式, 影響, 與原因

Multiplicity will exist for causes, failure modes, and effects
重複性存在於各個原因, 失效模式, 與影響之間

Failure Modes : Will share causes, and effects
失效模式 : 不同的失效模式會有共同的原因與影響

Causes : The reasons for failure, can be one or many for a given failure mode
原因 : 某個失效的 (多個) 原因, 可能是另一個失效模式中一或多個的原因.

Effects : The results of the failure, can be one or many for a given failure mode
影響 : 某個失效的 (多個) 結果, 可能是另一個失效模式中一或多個的結果.
Failure Mode 3
Failure Mode 1
Effect 3
Effect 2
Effect 1
Cause 4
Cause 3
Cause 2
Cause 1
Failure Mode 2

Error! No text of specified style in document.Failure Mode Effects Analysis, Continued
FMEA分析, 续前页

Define the scope for the FMEA, cont.
定义FMEA的范围, 续前页
Step 7
List the effects, causes, and current controls for each failure mode
Include input from customer and knowledge experts
步骤七
列出每一个失效模式可能产生的所有影响, 原因, 与目前的管制办法
将客户与专家的意见包含在内

FMEA; Step by Step
FMEA; 逐步展開

7 List the effects, causes, and current controls for each failure mode
列出每一個失效模式的所有影響, 原因, 與目前的管制辦法

Example:
舉例

Failure Mode Effects Analysis, Continued
FMEA分析, 续前页

Define the scope for the FMEA, cont.
定义FMEA的范围, 续前页
Step 8
Assign ratings for Severity, Occurrence, and Detection
Work to reach team consensus
步骤八
列出严重性, 发生机率, 和侦测能力的评比等级
致力于达成小组共识

FMEA; Step by Step
FMEA; 逐步展開

8 Assign ratings for Severity, Occurrence, and Detection
列出嚴重性, 發生機率, 和偵測能力的等級

Example:
舉例

Failure Mode Ef