Why Why Analysis Training Material

3x5 Why-why Analysis- A new approach for root cause analysis

1st Supplier Quality Day * 27NOV09

ST Shenzhen Plant

3x5 Why Why Analysis Content

2

A. The 3x5 Why Project Background

B. The 3x5 Why Method

C. The 3 x 5Why Focus

D. Templates

ST target is to share with our suppliers a common approachfor problem solving methods especially for “3x5 Why why “tool , to get complete, exhaustive FA report and to avoid any recurrence.

Naze-Naze / 3x5Why-Analysis Project Background

3

A. The Naze-Naze ProjectBackground

* Naze = “Why” in Japanese

4

The Situation1.The Need of our Customers

* To understand each 8D-Report from semiconductorand passive suppliers in depth

* To understand if the problems are solved in a waythat they never reoccur

Remark: Having reached ppm-level, our customer

fails enable ST and their customers /

suppliers to look at each 8D-Report in depth.

2. Improvement of 8D-Quality by Why-Why-RCA (Root Cause Analysis)In 2009, ST takes the next step and has started a project with our key suppliers.Focus on:

* Implementing Why-Why-Analysis for non-conformance and non-detection aspectsincluding system root causes

* Getting a common understanding of a sustainable problem solving process * Having a comprehensive documentation of each failure which is understandable

on a general technical knowledge level for our customers & management. Hint: This project is part of the 8D improvement initiative which is measured acc. Toyota

scoring methodology

寻根究底寻根究底寻根究底寻根究底


5

Motivation

� ST is the Top 3 automotive electronics supplier.

� All automotive customer request is “ZERO FAILURE”

However, ST devices didn’t reach the target :

• some failure were reoccurrences, special caused by quality excursions material.

• quality level is improving very slowly.

⇒there is a strong need for persistent improvement

• requires systematic application of lessons learned

• prerequisite: full understanding of real root causes (technical and non-technical)

=> method: 5 why analysis (naze naze), from Toyota


6

Role of Naze-Naze Champions

Internal and Supplier’s 5Why-Champion

Name: - Reviewed and Agreed by STM management

Task: - Leading of internal 5Why project, roll-out to all divisions and plants, Develop to all key suppliers.

- Encourage and support 8D-Engineers in applying the 5Why problem solving method

- Assure that technical & systemic root cause is analyzed and eliminated for “prevent” and “escape” aspect=> avoidance of recurrence.

- To be trained and evaluated by ST QA.

- Involving management team into Naze-Naze Method.


7

B. The Naze-Naze Method

Naze-Naze / 5Why-Analysis Method

8

Historical Background

Although the 5-Why problem solving technique has been popularized by the Japanese, this common-sense concept has been around for quite some time.

• For want of a nail a shoe (hoof) was lost,• for want of a shoe a horse was lost,• for want of a horse a rider was lost,• for want of a rider an army was lost,• for want of an army a battle was lost,• for want of a battle the war was lost,• for want of the war the kingdom was lost,• and all for the want of a little horseshoe nail.

John Gower‘s <Confessio Amantis> dated approximately 1390 AD.The earliest known written version of the rhyme above (often taught to British children)


9

Historical Background (cont.)

One of Ohno´s habits was to repeat asking

1. why the problem happened

2. why the problem was not prevented

-why–why-why-why…..

until the real root cause was found.

This habit has been preached to overseas

transplants of Toyota.

All Toyota employees are trained through their daily jobs to find out problems, root causes, countermeasures in this way.

His habit became a Toyota´s culture.

This culture is one of the keys of Toyota´́́́s

success today, that is realized by enthusiastic problem finding skill of every employee.

Having no problems is the biggest problem of all

Mr.KAIZENMr.KAIZENMr.KAIZENMr.KAIZEN „„„„TaiichiTaiichiTaiichiTaiichi OhnoOhnoOhnoOhno““““ (1912(1912(1912(1912----1990)1990)1990)1990)

Former executive vice president of Toyota

who established Toyota-Production-

System, which is known by “Kanban”.

His philosophy is still alive in today's

Toyota way.

"Ask ‘why’ five times about every matter."

1. "Why did the robot stop?"

The circuit has overloaded, causing a fuse to blow.

2. "Why is the circuit overloaded?"

There was insufficient lubrication on the bearings, so they locked up.

3. "Why was there insufficient lubrication on the bearings?"

The oil pump on the robot is not circulating sufficient oil.

4. "Why is the pump not circulating sufficient oil?"

The pump intake is clogged with metal shavings.

5. "Why is the intake clogged with metal shavings?"

Because there is no filter on the pump.

Link to the information source:http://www.asahi.com/jinmyakuki/TKY200509290213.htmlhttp://www.toyota.co.jp/en/vision/traditions/mar_apr_06.html

Naze-Naze /5Why-Analysis Method

10

Purpose of Naze Naze Analysis (5 x Why)

• Question:

How are you sure that your Naze-Naze Analysis is

performed properly?

• Answer:

When real root causes are identified,

there should be no reoccurrence of failures!

• The purpose of Naze-Naze Analysis:

To prevent reoccurrence of failures by implementing correct countermeasures on real root causes


11

What does “Problem” mean?

“Problem” is defined as

a gap between

“the way it should be”

and “the way it is”.


12

Problem description First step of problem solving!

If a problem is described wrongly,the result of problem solving will be also wrong.

Example of wrong description This is not a joke!Real example from a workshop with

engineering colleagues

Customer give us feedback very late when a delivered sample was out of spec., and we can not make improvement timely.

An out-of-spec. sample was produced and delivered to customer.

Think from customer’s view

Then, describe “standard” and “actual” in comparison


13

Basics of Naze-Naze Analysis

What to do

Grasp the situation

Pursue root causes

Implement effective C/M

C/M to prevent areoccurrence

Why to do

No reoccurrence should happen when the real root cause is fixed

Analyze with GENCHI-GENBUTSU

1. Organize & narrow down the problem

A complex problem � plural individual problems

2. Localize the problem

Perform GENCHI-GENBUTSU

3. Evaluate the situation of occurrence

Grasp the pattern

1. Shift from “reactive firefighting” to “preventive countermeasure”

Firefighting will result in reoccurrence

2. Master the key points of Naze-Naze to pursue real root causes

Grasp every factor of the failure regularly, orderly

Fix the real root cause and never let it reoccur


14

Grasp the situation accurately

Shortcut to real root causes!

3 elements to grasp the situation

① Organize and narrow down the problem

② Localize the problem

③ Evaluate the situation, how the problem

happened

Preparation for5 x Why

Initial Problem Perception

(large, vague or unclear)

Clarify the problem

Locate the Point

of cause

Locate the Point

of cause

to clarify� what� when� where� who� howin GENCHIGENBUTSU


15

Initial Problem Perception

(large, vague or unclear)

Clarify the problem

Locate the Point

of cause

Point of cause

Basic Cause/EffectInvestigation

Direct Cause

5 Whyinvestigation

1

2

2

3

4

5

6

Root Cause

Countermeasure

Follow Up and Check

GRASP THE SITUATION C

AUSE INVESTIGATION

Source: TMUK PPS

把握真实情况

进行原因调查分析

5 x Why is a keystep in theproblem solving


16

Grasp the situation accurately ・・・・・・・・・・・・1. Organize and narrow down the problem

Often a detected failure is a combination of complex problems

＜Example＞＞＞＞ Contamination on a product


17

Grasp the situation accurately ・・・・・・・・・・・・2. Localize the problem

Go back the processes from where the problem was detected

＜Example＞＞＞＞ Iron ball particle on a product


18

Grasp the situation accurately ・・・・・・・・・・・・Localize the problem in the history

If different direct causes were set in different timing or many personswere involved, list up all the events chronologically with evidences.

Evaluate each action if it was correct or not. Email, letter,documents, etc…

Examp

le

History

chartExample


19

Grasp the situation accurately ・・・・・・・・・・・・3. Evaluate the situation, how the problem happened


20

Fact analysis ・・・・・・・・・・・・find important factors

• Compare no problem time and problem time

• If not yet clarified, use Ishikawa diagram

• Always consider with 5M1E

5M1E

Man Machine Material

Method Measurement

Environment


21


22

For your successful Naze-Naze analysis

Understand the function and construction of the object well

• Product: understand the function and construction with parts,

drawings, etc…

• Management: confirm the process and function with working process

flow, rules, documents, etc…

• Search in two dimensions of “Produced” and “Delivered”

Non-conformance Non-detection


23

Drill for important factors deeper withNaze-Naze analysis

Do not jump immediately to investigate countermeasures.

Do Naze-Naze analysis to search real root causes.

Repeat asking “why” at least 5 times.

However this does not mean to repeat asking

meaninglessly “why” just 5 times,

but to find the real root causes.

Direct Cause

5 WhyInvestigation

RootCause


24

Difference between “containment” and “preventive” measures

＜Example＞＞＞＞ Machine stop


25

Difference between “Technical” and “System” root cause

＜Example＞＞＞＞ Machine stop


26

Example entered into excel-template


27

How Yokoten works in Toyota *Depending on the severity, escalation level is decided.

C/M should be implemented not only in technical aspect, but also system aspect**.

水平扩展水平扩展水平扩展水平扩展、、、、水平展开水平展开水平展开水平展开

Horizontal Deployment


28

Key Points：：：：

① Define “1st Why” from principle

② Describe only things differing from normal state

③ Verify the hypothesis as soon as a hypothesis is made

④ Do not diffuse the problem (avoid subjective issues)

⑤ Avoid searching for causes under psychological (心理上的心理上的心理上的心理上的)aspects

⑥ Describe simply (not two facts in one sentence)

⑦ Avoid ambiguity (含糊不清的unclear expression like “bad” or “insufficient”)

⑧ Clarify the comparative object when an adjective is used

⑨ Repeat “why” until a cause which can lead to a preventive

countermeasure is found to avoid a reoccurrence

⑩ Read backwards and confirm if Naze-Naze story is correct


29

① Define “1st Why” from principle

Focus on the problem phenomenon and define “1st Why” upon the principle of the problem

Problem 1st Why 2nd Why

Principle: something very basic


30

Thoroughly Pre-Investigation first

These 2 causesare to be found

throughthoroughly pre－－－－investigation.They are not

necessarily partof 5Why.


31

② Describe only things differing from normal state

< Bad example >

Dust levelincreased inclean room

Machinescreate dust

Machinesare

operatedwith fullcapacity

Productionvolume is

big

Demandincreased

No business can be continued with this root cause !


32

③ Verify the hypothesis as soon as a hypothesis is made

• Verify the hypothesis immediately if possible, even during Naze-Naze analysis.

• Verify by facts based on: SANGEN-SHUGI (Genba 现场现场现场现场, Genbutsu 现物现物现物现物, Genjitsu 现实现实现实现实), interview, reproduction test, etc…

Principle of the three “Gen”s – real place, real thing and reality.

Two methodologies:

my eyes and my legs. These are all I need to see, to judge, to consider, to decide.


33

④ Do not diffuse the problem

⑤ Avoid searching for causes under psychological aspects

It is difficult to make effective countermeasures against mentalaspects to prevent reoccurrence

< Bad example >

< Bad example >

Motoroverheate

d

Insufficientlubricant

Lubricantforgotten

Insufficientmaintenancemanagemen

t

Managerdoes notknowGENBA

Wrongmanager atthe post

Mr.A gothis headinjured

Mr.A hit hishead at theedge of the

ceiling

Mr.A did notpay

attention

Mr.Awas

careless

Be carefulwhen walking

Why Why Why C/M

The story was diffused dueto missing description ofwhat “insufficient” is

Avoid subjectiveissues, i.e.

＜Bad example＞personal skills


34

⑥ Describe simply

Describe simply with subject + verb

Do not describe two facts in one sentence

（risk to miss other causes)

+ when, where, how, etc…

Only 1 subject in one sentence

Be careful with „and, or, therefore, because, thus“< Bad example >

The battery has not been replaced for long time and the pointer cannot be turned on.

Separate into 2 sentences

The battery has not been replaced for long time The pointer cannot be turned on

The battery has run down

The battery has run down

The spring lost contact with the bulb

More potential causes are

successfully found!

Problem

Problem

The pointer cannot be turned on


35

⑦ Avoid ambiguity

Describe concretely

Examples of inappropriate texts (to be avoided)

XX is bad XX is insufficient XX shortage XX not thoroughly done

Operator not enough experienced

Operator did not remember the changeover procedure

Operator did not know where the stop switch located

Inexperienced operator was disposed at this process

⑧ Clarify the comparative object when an adjective is used

XX is too big for YY XX is bigger than YY XX is longer than YY

The bolt diameter is big

Bolt diameter is too big for the hole diameter

The hole diameter is too small for the bolt diameter

Describeconcretely

X

X


36

⑨ Repeat “why” until a cause which can lead to a preventive countermeasure is found to avoid reoccurrence

A containment measure cannot prevent a reoccurrence. （See Page 4）Considering the daily operation, stop “why” when a preventive measure which we can maintain is found.

⑩ Read backward and confirm if Naze-Naze story is correct


37

Practical hints for your problem solving workshop*

Team member selections:

• Expert team + the persons who were directly involved in the problem.

This is not to punish the individual faults, but is to perform “grasp the situation” with facts.

• Manager

Question technique:

• During “grasp the situation”, avoid questioning based on assumptions and concentrate on gathering facts. Otherwise this might guide the team into a wrong direction.

Manager’s attitude:

• Think about why the problem was not predicted nor discovered bymanager. Is there anything to improve?


38

Last but not least:

It is necessary to keep on learning in your dailywork in order to improve your Naze-Naze skills.

Is it a reoccurrence?「Product B was mixed in product A」After a measure was implemented「Product C was mixed in product A」


39

Practical hints for successful Yokoten*

� For a successful Yokoten, the key point is in “receiver side”.

� If the product or process is different, it is easy to excuse “not applicable“.

� Instead of saying “not applicable” quickly, think how the Yokoten case can be interpreted to your own processes.

� Every case is an opportunity of On the Job Training.


40

Before you sign on a problem solving report:

• Is 5 x Why logically done till system aspect?

• Are you convinced that the problem will not happen again?

• Is the report easy-to-understand from customer’s view?

Can you present it to your customer?

Go back with “therefore”

Mindset of coach

The reason that students (my colleagues) are not learning isbecause the teacher (I) is not teaching.

41

C. The 3 x 5Why-Focus

Naze-Naze / 3x5Why-Analysis Focus

42

What is the 3x5Why-Root Cause Analysis?

� General:

• The 5-Why Root Cause Analysis technique is a practical and proven tool for elimination of root causes.

• Failing to address the deeply rooted seed of the problem means it will likely recur.

�The Method:

• The problem-solver simply asks a Why-question approximately

five times in series to analyze a certain aspect.

• Through the 3x5Why-method the root cause can be discovered…

1. in the Manufacturing process to PREVENT failures (non-conformance)

2. in the Quality test inspection process, in order to PROTECT the customer from test escapes (non-detection), and

3. to identify/PREDICT weaknesses in the (Quality) Management or System, in order to exclude recurrence (-> learning organization towards zero defect).

Because

Why


43

Avoid this Pattern

The following sequence of Questions should not be followed:


44

Basic Solution Pattern

The following sequence of Questions is recommended:


45

Identification of System-Rootcause

Purpose of 5Why-Analysis:

Identification of the individual

(1) Technical and

(2) System Root CauseDrill Deep

� Definition System Root Cause:� Organizational causes, that lead to a deviation.

Example: Missing work flows, unclear descriptions and/or responsibilities not defined

� Solution or definition of measures is up to the management�System Root Cause

� Recommendation:� In the Fishbone-branch for „methods“ organizational weaknesses

can be considered.


46

Summary Why-Why Analysis Ask for system root causes foreach technical root cause

non-detection: same as above!

47

D. Templates

Naze-Naze / 3x5Why-Analysis Template

48

Naze-Naze / 5Why-Basic Word-Template Corrective Action with Responsibility Date 1 x 5Why : A DD.MM.YYYY NON-

Define Problem CONFORMANCE (PREVENT) ASPECT: 2 x 5Why : B DD.MM.YYYY

Use this path for the specific

nonconformance C1 DD.MM.YYYY being investigated

3 x 5Why : C2 DD.MM.YYYY WHY?

NON-DETECTION Technical

Root Causes System

Root Causes (PROTECT) ASPECT: WHY? Use this path to

Investigate why the problem was PREDICT ASPECT :

Use these fields to investigate the

systemic root cause

not detected WHY?

WHY? WHY? A

WHY? WHY?

WHY? WHY? C1 Ref. No. (RMA, DMR, etc)

… .

WHY? B Date

DD.MM.YYYY

WHY?

Product / Process Location Content Latest Rev Date

Electrical component City/ Country DD.MM.YYYY

WHY? C2

Problem Resolution Complete

Communicate to Customer Date: DD.MM.YYYY Process Change Break Point Date: DD.MM.YYYY

Implement System Change Date: DD.MM.YYYY Lessons Learned:

The template (word

or excel file) can be used as a

It is not mandatory to use exactly

this form, but it might be a help in tracing back

the systemic root cause for both aspects,

non-conformance and non-detection.

summary sheet for root cause investigation.


49

Define Problem: TECHNICAL SYSTEMROOT-CAUSE ROOT-CAUSE

Result Investigation Report:

NON-CONFORMANCE (PREVENT): Use this path for the specific non-conformance being invested

Why? Why? Why? Why? Why?

NON-DETECTION (PROTECT): Use this path to investigate why the problem was not detected

Why? Why? Why? Why? Why? Why?

SYSTEM-ROOT CAUSE (PREDICT)Use these fields to investigate

the systemic or Management-Root Cause

...

Excel –

templa

te


50

Example: Processability due to bad solderability


51

Example: Weak Processability due to bad solderability (cont.)

Naze-Naze / 3x5Why-Analysis

52

Thank you for your time.

Questions / Feedback:Mail to:[email protected]@[email protected]@ST.COM

Documents

Why Why Analysis Training Material