Understanding 6 Sigma

8/3/2019 Understanding 6 Sigma

1/101

Understanding 6s (Six Sigma)


2/101

What is 6s activity?

Why should we do 6s?How to Launch 6s ?

6s Project Road Map

Contents 6s


3/101

1. What are the statistics ?

Population & Sample

Sample

PopulationN 1,000

Measure 10 samples(Spec. : 1004)

You may say This Population is Good because all the samples data are locatedbetween LSL & USL. BUT, If you estimate the defect rate using statistical analysis,this population has the probability of 2.8% defects per unit.Then this is - we call - An epidemic quality defect level.

Measuring defect rate on process through an expanding statistical concept,we can use measuring process capability.

USL(UpperSpecLimit)

LSL(LowerSpecLimit)

96 97 98 99 100 104101 102 103

Total inspection isimpossible !

Statistical variables(mean, variance)estimate population

6sWhat is Six Sigma Activity ?


4/101

USLUSL

T

USLUSL

T

USLUSL

T

Precise but not Accurate

Accurate but not Precise

Shifting to Target &Reducing Variation

Shift to Target

ReducingVariation

2. Solution of the Practical Problem

Objectof 6s isShift toTarget

Reducingvariation



5/101

6s Quality means that areaof the estimated normaldistribution is located betweenUSL&LSL with 6 s.

In that case area ofthe outlier spec.(In other words estimateddefects) is just 3.4 PPM.

* s : Standard Deviation Statistic index measures how much is data apart from target value

3.4ppm

Target USLLSL

+ 6s- 6s

+ 3s- 3s

6.68%

3. What is the 6s concept ?

Statistical Definition of 6s

3s

6s



6/101

6 3.4

5 233

4 6,210

3 66,807

2 308,537

s PPM 1 misspelled word in all of the bookscontained in a small library

$340 indebtedness per $100 millions assets

1.8 minutes per year

1.5 misspelled words per page in a book

$6.7 millions indebtedness per $100 millions

assets

24 days per year

6s as the Business Strategy

3. What is the 6s concept ?6sWhat is Six Sigma Activity ?


7/101

In all Design, Manufacturing, and SVC processes Applying for 6s statistic Tools & Processes To find factors causing defects

Acting the Analysis and Improvement

Through the Defect Reduction, Increase Yield

& Total Customer Satisfaction

Management Innovation Tool contributes to

Management Output

Achieving3.4 PPM

(3.4 Defects Per Million)

What is 6s activity?

PPM : Parts per Million

6s as the Activity

3. What is the 6s concept ? 6sWhat is Six Sigma Activity ?


8/101

Ground Fruit Logic and Intuition

Wall of 3s

Low Hanging Fruit Seven Basic Tools

Bulk of Fruit Process Characterization and

Optimization

Fruit-bearing 6s Sweet Fruit Design for Manufacturability

Wall of 4s

Wall of 5s

Harvesting the Fruit of 6s4. 6s as the Business Strategy 6sWhat is Six Sigma Activity ?


9/101

5. 6s Application

Selecting CTQ to meet customer needs Decision reasonable ToleranceGuarantee of the CTQs capability analysis

Improvement serious problem using S/W Real Time Monitoring system

CTQ Control system

Improvement cycle time and accuracy Cost Improvement

Guarantee for the Design completionin developing stage

Quality assurance in manufacturingstage

Maximizing for sales & SVC

6s is a tool that applies to all business systems - Design, Manufacturing,Sales and SVC

R&D

6s

Manufacturing

6s

De-

sign

Sales

&SVC

Mfg.

6s

Transaction6s

Design

Mfg.

Sales&SVC



10/101

Identify Customer-DrivenCTQ (Critical to Quality)

Characteristics

Identify Key Processes thatcause Defects in a CTQ

Characteristics

For Each Product orProcess CTQ

Measure, Analyze, Improve,& Control

6sis a rigorous analytical

process for solving problem!!!

6. 6s Activity Process

1. Who are your customers?- Internal / External

2. What do you provide your customers?3. What is critical to quality for your customers?

1. What are your internal processes forproviding your product or service CTQs toyour customers?

2. Where do defects occur in these processes?

D

Practical Problem Measurement System Yield Calculation

Process Mappings Calculation

Benchmarking

Hypothesis Testing

Cause & Effect Diagram

DOE Brainstorming

Action Workout Techniques Piloting

Control Mechanism Control Chart

Procedures

M

A

IC

6s Activity Process(manufacturing & Transaction)

*

**

* CTQ(Critical To Quality) : Your customers feel that characteristic of product, service or process is critical.** D : Define



11/101

90 11

7. Comparing other tools

- Define/

Measurement- Variance ofCTQ

- Present con-dition Analysis

- Improvedby expertsIdea

- Control bycontrol chart

- Process4M control

Measure

- Symptoms- Frequency

- Analysis for

statistics- Effect analysiscaused factors

- Optimizing

condition bystatisticalanalysis

Others

6s

- Discrete Data

- Difficult to apply practicalproblem because ofcomplextity

- Discrete+Continuous

data- Easy to apply becauseof supporting statisticalsoftware.

Analysis Improvement Control

- Control by

PTS(CTQ,Benefits)

Focusingexperience/technology

* PTS : Project Tracking System

*

By Improvement Process



12/101

7. Compare with other tool

Detecting process

defects

Product managingcompare with spec.

Judging each

persons Know-How

Manual Datagathering & analysis

Control process

variation

Judging the statistic

Data

Simple & Effectiveanalysis using theS/W

Prevention Controlvital few factors

Managing Tool Improvement Tool

Selecting Line Do process FMEA

- Selecting Cost issueprocess view of customer

Conform CTQ process Sorting the process

- Just need control process- Important control process- Law application process- Variation improvement

100ppm / 6s applicationaccording to sortingprocess

100ppm / 6s

100ppm 6s100ppm / 6s Application



13/101

CTQ(Y) = F( X1, X2, X3, ... Xn )

Y X

Focusing Point

6sactivity is selecting the cost issueproblem on some system in view of

customer.This is we called CTQ and

We achieved 6s target throughthe 6s process just selecting CTQ

Also, 6s activity is focusingthe causing factor(x1,x2...xn),not selecting CTQ itself

Dependent

Output

Effect

Symptom

Monitor

Independent

Input-process

Cause

Problem

Control

X factor effects on CTQ(Y) hasthe vital few 20% & trivial many80%.

8. 6s Philosophy6sWhat is Six Sigma Activity ?


14/101

We dont know what we dont know.

If we cant express what we know in the formof numbers, we really dont know much about it.

If we dont know much about it,we cant control it.

If we cant control it,we are at the mercy of chance.

8. 6s Philosophy6sWhat is Six Sigma Activity ?


15/101

Generally controlled F-Cost has small portion considering of Hidden Loss

Traditional F-Cost( Easy Definition)

Inspection

Scrap

ReworkReject

SVC

Loss Opp. Sales

Delivery Delay

Brand Image Down

Office Loss Over Storage

Over Rework

Long cycle time

Design ChangePotential(Additional)F-Cost(Difficult to measure)

1. Quality & Failure Rate6sWhy do we do Six Sigma ?


16/101

2. Paradigm Shift

Old Belief New Belief

$ $

Quality Improves

Internal&External FailureCosts

Appraisal& PreventionCosts

4s

Increased Qualitymeans Higher Cost

4s 5s 6s

$

$

Quality Improves

Internal &External FailureCosts

Appraisal& PreventionCosts

Increased Qualityreduces Total Cost

Internal Failure : Scrap / Remake / Supplier ReworkExternal Failure : Cost to Customer / Warranty Cost / Compliant Adjustments / Returned MaterialAppraisal : Inspection / Test / Quality Audits / Test EquipmentPrevention : Quality Planning / Process Planning / Process Control / Training

Paradigm Shift for Quality

The high quality producer is the low cost producer not expensive.

6sWhy do we do Six Sigma ?

Wh d d Si Si ?


17/101

Practical Meaning of 99% Good

20,000 lost articles in mail per hour.

Unsafe drinking water almost 15 minutes each day

5,000 incorrect surgical operations per week

2 short or long landings at most major airports each day

200,000 wrong drug prescription each year

No electricity for almost 7 hours each month

4s = 99.38%

2. Paradigm Shift


Wh d d Si Si ?


18/101

Traditional Approach 6s Approach %(Defect Rate)

Discrete Data

Satisfaction for MfgProcess

Spec Outlier

Experience + Job

Bottom Up

Mfg Process

s Discrete + Continuous Data

Customer Satisfaction

Variation Improvement

Experience + Job +

Statistical Ability Top Down

Design, Mfg, Sales, SVC

ISSUE

Index

D a t a

Target

Range

Method

Action

Application

Traditional Quality / 6s Quality Method

3. Character of 6s 6sWhy do we do Six Sigma ?

Wh d d Si Si ?


19/101

At the beginning of 80s, In the Japanese

market, Motorolas beeper lost its name

value because of the quality differencecompared to Japans

In 1981 they tried to meet a challenge to

improve quality 5 times in 5 years and they

couldnt.

They developed a consistent process base

on statistical knowledge.

In 1987, they established 6 goal

as a key initiative.

In 1995 GE launched 6 process

to overcome a difficult business

environment and to challengeWorld Class Quality.

They made new processes such as

Productivity,Inventory Return and NPI,

but improvement was delayed

because of defects in processes.

GE thinks World Class Quality is

big challenge. GE will focus on

6 process for next generation .

4. 6s Case Study

Start : Motorola Prosperity :GE

Start & Prosperity


Wh d d Si Si ?


20/101

MOTOROLA T I G E SONY

Introduce

Outcome

Character-ristics

Remarks

1987 1988 1995 1997

Q. Cost Down Q. Cost Down Q. Cost Down By 2000 years$3.2billion 1988:30% $3.8billion Train 2,000

1993:7.4% Black Belts

Origin of 6 Adopt to all Biz. First in Japan(Quality levelelevated 100 times

in 4 years)

Culture harmony TOP DOWN Train and do pjt. Consult withWestern & Oriental Quality Train 6 Academy

Cases of other companies

4. 6s Case Study 6sWhy do we do Six Sigma ?

Wh d d Si Si ?


21/101

Output of other companies

6s do the role of Boundaryless Behavior. Organization become learning & logical

Use 6s as worldwide common language. GE believes that 6s would take part

central role in the future.

G E

Motorola Motorola reached 5.5 level in 1992.Outcome is $3.2billion from1987 to 1992.

0200400600800

10001200

96 97 98

CostsBenefits

4. 6s Case Study

Qualitative outputBenefits


H t L h Si Si ?


22/101

1. Key Factor for Success of 6s2. 6s Operating system3. Project tracking system

4. Case study for Infra.

6sHow to Launch Six Sigma ?

H t L h Si Si ?


23/101

1. Key Factor for Success of 6s

Need Top Down DriveNeed Top managements strong will for 6.Top managements strong and periodical

announcement about 6 policy.

All employees must participate...

Not only manufacturing part, but alsononmanufacturing part should join the program

Focus on Customers requirements.

6s as Pan-Companys common standard.Common language .(CTQ, , Cp,Z ....)Avoid personal translation about 6.All of Goal and target are represented as scale. Basic process for all of projects.

Start at Customers voice.CTQs from Customers voice,

Improve the item which has big impact first!

Need Training Program for All employees

Complete understanding for 6 program. Hard training for all employees. Need resource investment resolutely.

Construct Infra Need successful case study project. Resource reformation for organization and system. Reasonable appraisal and reward system.

System requirement Methodology


How to Launch Six Sigma ?


24/101

* Champion Review : Decision making meeting that controls progress by project steps(Selecting theme Output review)

Champion

- 6s Operating

Project Team

- Operating Project- Achieving 6s level for CTQ

MBB(Master Black Belt)

- Supporting 6skill

Coaching/Supporting

Request supporting

Chief of executive division

- 6s Driving- 6s Involvement & Commitment

ChampionReview

2. 6s Operating system6sHow to Launch Six Sigma ?



25/101

2. 6s Operating system

Champion

Definition

Chief of 6s operating

Chief of business groups(Chief of OBU, BusinessExecutives, Chief ofsubsidiary)

Roles

Set the 6s goal Assignment subject for total optimization Guide direction and goal of Project

It is very important that the Champion gets involved in project and take ownership for 6s

- Present the Vision

Monitor and support through Champion ReviewDirectly support to settle bottleneck for 6activity

- Involvement

Continuously lead Activity through strong commitment Evaluate Output and Share best practice with MBB

- Drive 6s Activity

Lead supporting all department in improvementand control step for 6s Project team

Deciding Investment and allocate resources Generate motives

- Support Project




26/101

2. 6s Operating systemMBB(Master Black Belt)

6s Technical Leader

Full Time Job for 6s

Complete MBB Course oracquire MBB Cert.

It is very important to select excellent MBB and continuously improving skill

Definition Role

- Support Skill

Coach BB/GB for 6skill and tools Level Up for 6s skill & tools

Share best practice

- Drive project results

Check the Project by 6 progress step Report champion about project status and output Assure benefits are real

- Support Projects Mentor BB / GB and Train individuals in tools Support settlement for 6sActivity Barrier continuous management and control for improved process




27/101

2. 6s Operating system

Main Job Role Requirements

Leading BB/GB Project Drive

Verity Output Training

6 Technical Leader Needs Stat. Skill

Propagate

More than 4 Projects&

Consulting More than5 Projects a year

Full Time ProjectOn TDR Theme

Execute Project Leader of Pjt. team Team member

training

2 Projects&

1 Project a year

Join Project byPart time

Execute Project Team Leader or

Member

2 Projects

Master

BlackBelt

BlackBelt

GreenBelt

Belt

Belt Certification




28/101

3. Project Tracking System

PTS Flow Benefit

- Update and control CTQ of Closed Project

- Easily manage and report for Project status

- Evaluate reduction cost of 6sProject- Share Project information

- Monitor 6s Project status

Project Theme/Z value/Reduction cost

Amount

By Division/OBU/Product/Model

AllProjects

Belt

PTSChampion,

Owners

ProjectReviews

- Defect Data,Goal- Project status- Results- Weekly update

Weekly Review Confirm cost benefitsBenefits

Check & monitor

*

* PTS : Project Tracking System




29/101

4. Case Study For Infra.

6sTrainingMaterial

Training ForAll Employees

Planning6sStrategy

- Briefing 6s

Process

- Planning 6sStrategy/Goal

ConstructIT System

- Impove Chronic

Defects: Minitab S/W

- OptimizeProcess IT: Real Time

Monitoring: Data Base

For CTQs

- PTS: Project Tracking

System

- Intoduce 6s

: All Employee

- 6s GBTraining Prg.: Engineer,

Staff

- 6s WBTraining Prg.

: Supervisor

Organizing6sTeam

- Due part

MFG : QA TeamLeaderR&D : Chief of

Lab.

- Organize 6sSurport Part

:2~3 person/OBU

Organize6s Team

- Training for Employees

- Training for Boards Project Review

- MBB & BB : 80/Year

- Training: 2,400 person

Case Study

- 6s Team

- Case Study: 1 / OBU

* Case :LGE Home Appliance Division.


What is Six Sigma


30/101

6sSix Sigma is

a data basedmethodology

for pursuing

continuousimprovement

by reducing process variability.

It requires

a thorough process and productunderstanding

and

is clearly focused on

customerdriven expectations.

What is Six Sigma

6


31/101

6s

Our processes are parts of a larger customer processes

End to End Processes

6


32/101

6sWing to Wing !

6


33/101

6sDefect and DefectiveDiscrete Data can be

A Defect

A single characteristic that does not meet requirements

A Defective

A unit that contains one or more defects

6


34/101

6sUnit (U)

The number of parts, sub-assemblies, assemblies, or systems inspected or tested.

Squares: 4 units

Opportunity (OP)

A characteristic you inspect or test.

Circles: 5 opportunities per unit

Defect (D)

Anything that results in customer dissatisfaction. Anything that results in a non-conformance.

Black circles: 9 defects

Three characteristics of an opportunity:

Customer cares about it.

Independent

Can actually happen

What is Six Sigma

6


35/101

6sFormulas

Defects per Unit

DPU = D/U

9/4 = 2.25

Total Opportunities

TOP = U*OP

4*5 = 20

Defects per Opportunity (Probability of a Defect)

DPO = D/TOP

9/20 = .45

Defects per Million Opportunities

DPMO = DPO*1,000,000

.45*1,000,000 = 450,000

What is Six Sigma

6D fi Ph


36/101

6s

The Define Phase

Define your customers & their expectations, team goals, project boundaries, what you willfocus on, and what you wont. Define the process you are striving to improve by mapping theprocess.

The key deliverables for the Define phase are:

Customer CTQs derived and documented

Team charter documented and reviewed with Champion

Validated process map completed

Define Phase

6


37/101

6sPurpose of the Charter

Clarifies what is expected of the project

Keeps the Team focused

Keeps the Team aligned with organizational priorities

Transfers the Project from the Champion to the Project Team

Team Charter

6


38/101

6sThe Project Charter contains :

Business Case

Explains Why is the project important to be done

Problem & Goal Statement

Describes the pain in clear, concise and measurable terms.

Project Scope

Milestones / Project Plan

Roles / Responsibilities

Team Charter - Contents

6


39/101

6sExample

Business Case

Financial (loss/gain) from (current/goal) : Rs.2.1 million

Problem Statement

Measure : field returns of tractors with oil leakages

Current Defect Rate : 32.8%

Period : last 8 months over a production 1000 tractors

Where : North Region

Goal Statement

New Defect Rate : 6.2%

Rationale : competitive performance

Period : over next 3 months production (@ 125 tractors per month)

Business Case, Problem & Goal Statement

6


40/101

6s What process will the team focus on ?

What are the boundaries of the process we are to improve ? Start point ?

Stop point ?

What resources are available to the team ?

What (if anything) is out-of-bounds for the team ?

Under what (if any) constraints must the team work ?

What is the time commitment expected of team members ?

What are the advantages to each team member for the time commitment ?

Project Scope

6What is Six Sigma


41/101

6sWhat is Six Sigma

6


42/101

6s Should be preliminary, high-level project plan with dates

Should be tied to phases of DMAIC process Should be aggressive (Dont miss the window of opportunity)

Should be realistic (Dont force yourselves into correction rather than corrective actions)

Milestones / Tollgates / Project Plan

6T R l / R ibiliti


43/101

6s How do you want the Champion to work with the team ?

Is the teams role to implement or recommend ? When must the team go to the Champion for approval ?

What authority does the team have to act independently?

What and how do you want to inform the Champion about the teams progress?

What is the role of the Team Leader (Black Belt / Green Belt) and the Team Coach ( Master

Black Belt) ?

Are the right members on the team ? Functionally ? Hierarchically ?

Team Roles / Responsibilities

6COPIS A h f B i P


44/101

6sCustomer

Whoever receives the output of your process (Internal Customers / External Customers)

Output

The material or data that results from the operation of process

Process

The activities you must perform to satisfy your customers requirements

Input

The material or data that a process does something to or with

Supplier

Whoever provides the input to your process

COPISApproach for Business Processes

6

Wh t i Si Si


45/101

6sProcess Definition

A process is defined as a collection of activities thattakes one or more kinds of input and creates outputthat is of value to the customer.

Business Process Mapping

The model is applicable to both product and serviceorganizations.

Everyone receives inputs from suppliers, adds valuethrough their process, and provides an output oroutput that, at a minimum, meets the customersneeds and related requirements while trying to

exceed them. It is important to recognize that the end product for

the customer and the output of the process, for thepurpose of this model, are the same.

What is Six Sigma

6PROCESS MAPS - SIPOC


46/101

6sPROCESS MAPS SIPOC

6

Why Process Mapping ?


47/101

6sBenefits Of Process Mapping :

A structure for thinking through a complex process in a simplified, visible manner.

An ability to see the entire process as a team.

An ability to see that changes are not made in a vacuum and will carry through, affectingthe entire process down the line.

The magnification of non value-added areas or steps.

The ability to identify cycle times for each step in the process.

Why Process Mapping ?

6Measure Methodology and Deliverables


48/101

6sMeasure Methodology and Deliverables

6Deliverables of Measure


49/101

6sMeasure Deliverables

1. Identify the Measurable Customer CTQ

2. Define and Confirm Specifications for the Y

3. Ensure Measurement System is Adequate to Measure Y

Deliverables of Measure

6

Measurements get Attention


50/101

6sMeasure Objectives

Identify the project Y

Define the performance standards for Y including specification limits and defect andopportunity definitions

Validate the measurement system (Audit it for correctness / reliability; from which register /database, what field, what formula etc. would be used as a basis)

Develop a common reference document for all team members to promote clearcommunication about the purpose and methods for data collection and provide the linkbetween the data collection effort and the project goals

Collect the data

Characterize the data using mean and standard deviation

Measurements get Attention

6

Segmentation


51/101

6sSegmentation

An analysis technique that involves temporarily dividing a large group of data into smallerlogical categories to look for areas of very good vs. very poor performance

Can be used to understand which Xs drive variation of the Project Y

Collect segmentation factor data to be used for later analysis

Common Segmentation Factors

Common Segmentation Factors :

What type : Complaints, defects, problems

When : Year, month, week, day

Where : Country, region, city, work site

Who : Business, department, individual, customer type, market segment

Segmentation

Segmentation Helps Us Understand Variation In Project Y

6How to collect Data for Segmentation


52/101

6s Identify the factors for segmentation before you start collecting data

Make sure the segmentation factors can be measured reliably

Record the segmentation factors for each Y data point collected

Segmentation factors are typically easy to collect, so collect more segmentation factors ratherthan fewer

A proper segmentation done will ensure that when you want to use data for further analysis, itcan be massaged / stratified in various ways.

How to collect Data for Segmentation

6Step 1 : Identify CTQs and Project Y


53/101

6sStep 1 : Identify CTQs and Project Y

6Example - Arriving at CTQs


54/101

6sExample Arriving at CTQs

CTQs Are The Bridge Between Our Process Output And Customer Satisfaction.

6

Step 2 : Performance Standards


55/101

6sWhat is a Performance Standard

A Performance Standard is the requirement(s) or specification(s) imposed by the customer ona specific CTQ.

It answers the questions :

What does the customer want ?

What is a good product/process ?

What is a defect ?

Example :

Contracts : Terms of Loan, due diligence standards, time of delivery, warranty information

p

Performance Standard : Customer Specifications for a CTQ

6Step 3 : Validating Measurement System


56/101

6s

Actual Variation

Total Observed Variation

MSV MSV

MSV = Measurement System Variation

MSV is attributable to :

a) Person to Person (data collector) Variation

b) Measurement Equipment Variation

c) Variation due to Method of Collection or Environmental conditions

Step 3 : Validating Measurement System

Variation due to

Measurement System

6Base lining Current Process Capability


57/101

6sStep Tool Used Outcome

1. Collect Data against Y and seg

mentation factors

Segmentation, Data collection sheet/pla

n, Measurement System Analysis (Auditof Measurement System)

Validated Data for Y against vari

ous Xs

2. Study Shape ; Check normality Histograms, Normality Test (Anderson Darling)

Inference about the shape of the process output and closenessto normal distribution

3. Check for Stability Run Chart Presence of Clusters, Mixtures, Trends, Oscillation if any. for furt

her segmentation.

4. Calculate Basic Statistics of the Sample

Descriptive Statistics Mean, Median, Std. Dev., Normality, Quartiles

5. Calculate Present Process Capability

Process / Product Report ZST, ZLT, ZShift, Zbench,

In Case data not normal,and unstable, convert into DPMO to us

e the product Report.

6Normal Curve


58/101

6s

The Normal Curve is a graphical representation of the mathematical expression used todescribe a Normal Distribution.

This distribution is the result of a process. The mean is the average of the data points.

6Standard Normal Curve


59/101

6s

Whats the probability of being: greater than (less than) the mean ?

greater than (less than) 3 standard deviations ?

greater than (less than) -1 standard deviation ?

A randomly selected item has a 99.73% chance of being between -3 and 3 standard deviations from the mean.

Standard Normal Curve

6Why Standard Normal Distribution ?


60/101

6s

The probability areas remain the same for any given region under the normal curve regardlessof differences in variation.

Why Standard Normal Distribution ?

6ZLSL and ZUSL


61/101

6s

6Z Short Term, Z Long Term, Shift


62/101

6s

More the shift, more the process is unstable

, g ,

6Concept of Stability


63/101

6sp yA process is said to be stable if the process settings do not change significantly over a period of

time.A stable process does not have presence of :

a) Trends

Points going up or points going down

b) Oscillations

Alternate points going up and down

c) Mixtures

Mix of output from different sources/processes

d) Clusters

Visually distinct groups of data points

1

11

1

22

22

3

3

3

3

A Process can be checked for Stability by studying a Run Chart

6Understanding a Box Plot


64/101

6s

6Analyze Deliverables


65/101

6s

Deliverable:

Baseline Current Process

Tools:

Basic Statistics

Graphical Analysis

Sampling

Continuous ZST, ZLT

Normality

Discrete ZST, ZLT

Deliverable:

Statistically Define the Goalof the Project

Tool:

Benchmarking

Deliverable:

List of StatisticallySignificant Xs, ChosenBased on Analysis ofHistorical Data

Tools:

Process Analysis

Graphical Analysis

Hypothesis Testing

Regression Analysis

6Flow of Analysis Phase


66/101

6sPossible factors (Xs) affecting Y

Brainstorm using Fishbone/Cause & Effect Diagram and FMEA

Segmentation

on the possible Xs to identify areas of very good V/s very bad performance

Pareto

From possible Xs filter vital few Xs (causes)

Hypothesis Testing / Regression

Validate Vital Few Xs for their effect on Y :

Identify the critical Xs

which need to be controlled to get desired Y response

6

Types of Variation


67/101

6sCommon / Chance Cause Variation

Consists of many individual causes

Any one cause results in only a minuteamount of variation

Example :

Slight variation in raw material

Lack of human perfection in readinginstruments & setting controls

Cannot be economically eliminated

Process follows a predictable (statistical)pattern

GOK (God only knows)

Special / Assignable Cause Variation

Consists of just one or few individual causes

Any cause can result in large variation

Example :

Batch of defective material

Untrained Operator Faulty Set-up

Easy to detect & generally economical toeliminate

No specific pattern

HAK (Human Also knows)

6Tools to identify Sources of Variation


68/101

6sProcess Mapping

Understand process steps; narrow project focus

Pareto Chart

Prioritize items: narrow project focus

Cause & Effect

Understand problem: narrow project focus

FMEA

Identify and prevent failures; narrow project focus

Hypothesis Testing

Compare variation and Central Tendencies of two or more samples/populations

6Pareto Analysis


69/101

6s Used by Italian Economist Pareto as 80:20 Rule.

80% of the Wealth is with 20% of People.

Application in Quality states that 80% of our problems are caused by 20% of our activities.

Top 20 International Destinations Contribute 80% Traffic.

Works on principle ofVITAL FEW TRIVIAL MANY

6Pareto Diagram


70/101

6s

2 9 3 0 1 6 2 6 2 1 5 0 2 2 4 1 2 3 1 1 0 1 5 4 6 5 3 1 1 4 5 0 3 5 3 8 6 1 4 3 7 6 3 3

2 7 . 2 2 4 . 4 2 0 . 8 1 0 . 2 6 . 1 4 . 2 3 . 6 3 . 5

2 7 . 2 5 1 . 6 7 2 . 4 8 2 . 7 8 8 . 7 9 2 . 9 9 6 . 5 1 0 0 . 0

0

5 0 0 0 0 0

1 0 0 0 0 0 0

0

2 0

4 0

6 0

8 0

1 0 0

D e fe c t

C o u n t

P e r c e n t

C u m %

Percent

Count

USA UAE UK Singapore othersHongkongMalaysiaGER

Manydestinations

g

6Cause & Effect / Fishbone Diagram


71/101

6sPurpose:

To provide a visual display of all possible causes of a specific problem

When: To expand your thinking to consider all possible causes

To gain groups input

To determine if you have correctly identified the true problem

6Building a Fishbone Diagram


72/101

6s Brainstorm possible causes and attach them to appropriate categories

For each cause ask, Why does this happen?

The process of Ask why five times works well here. Get to the root cause.

Analyze results; any causes repeat?

As a team, determine the three to five most likely causes

Determine which likely causes you will need to verify with data

6Fishbone Diagram


73/101

6s

HIGH TIME OFRESTORATION OF

FIBER CUT

CommunicationDelay to FRT

Alarm notdetected

Availability of

EOW

Alarm-Comm. CT(SMS, Mobile)

Delay inMobilisation

Non Availabilityof FRT

Time / Day of

the Fault

Non Availabilityof Van/Spares

Delay inReaching Site

Location of FRTwrt site of fault

Time of Day /Season of ault

Availability ofRt. & Jt.Markers

Var. in Physical& Optical Dist.

OTDR Usage

Terrain of FaultSite

Localisation ofFault

Availability ofTemp. Labour

OTDRCorrectness

Availability ofRoW

Availability &Correctness

ABD

Availability ofRt. & Jt.Markers

Delay inSplicing

Lack of Skilledmanpower

Condition ofSplicing m/c

6FMEA Model


74/101

6sLinks Failure Mode to Cause and Effect

6

Types of Controls


75/101

6sTYPE-1 CONTROL (P-TYPE)

Controls which PREVENT the cause/failure mode from occurring, or reduce their rate of occurrence.

TYPE-2 CONTROL (D-1 TYPE)

Controls which DETECT the CAUSE of failure mode.

TYPE-3 CONTROL (D-2 TYPE)

Controls which DETECT the FAILURE MODE.

EXAMPLE

Take a stage of heat treatment process.

The failure mode identified is : Hardness Not OK.

So lab tests to check the hardness are TYPE-3 controls.

Suppose the causes identified are improper temperature (less or more than allowable) and time.A buzzer which blows when temperature is above or below the allowable value is a TYPE-2 control.

Patrol inspection to monitor the temperature is still TYPE-2 control.

A feed back control system to regulate temperature when it goes above and below the allowablevalue is a TYPE-1 control.

6

What is FMEA


76/101

6sFMEA (Failure Mode Effects Analysis)

A structured approach to:

Identify the ways in which a process can fail to meet critical customer requirements

Estimate the risk of specific causes with regard to these failures

Evaluate the current control plan for preventing these failures from occurring

Prioritize the actions that should be taken to improve the process

Identify ways the product or process can fail. Then plan to prevent those failures.

6Potential Effects of Failure


77/101

6s See the effect of failure on :

Next Operation

Subsequent Operation Part

Vehicle

Customer

Government Regulations

SEVERITY Seriousness of effect

(5 to 8 rating Significant)

(9 to 10 rating Critical)

6Potential Causes of Failure


78/101

6s Identify process deficiencies at that particular stage which results in that failure mode.

As far as possible assume incoming part/material to an operation are correct. If nonthere, then only see whether there is some failure mode of previous operation.

Treat design to perfectly O.K.

OCCURRENCE

Probability that A particular cause will occur &

And will lead to that particular failure (Cpk can be used).

6Current Process Controls


79/101

6s Consider only those controls that will be used to detect the failure mode (Assumption

Failure has occurred).

Note : Controls intended to prevent or reduce the occurrence of a cause of failure modeare considered for occurrence rating.

DETECTION

Probability that present controls will detect a failure mode or detect cause (Assume

failure has occurred)

Example of 1000 sheep(low occurrence not necessarily means low detection)

D D Effects D D P Effects O

6

FMEA Calculations


80/101

6sRisk Ratings

Severity (SEV) How significant is the impact of the Effect to the customer (internal or external)?

Occurrence (OCC)

How likely is the Cause of the Failure Mode to occur?

Detection (DET) How likely will the current system detect the Cause or Failure Mode if it occurs?

Risk Priority Number

A numerical calculation of the relative risk of a particular Failure Mode

RPN = SEV x OCC x DET This number is used to place priority on which items need additional quality planning

6FMEA Template


81/101

6s

6Guidelines for Occurrence Ratings


82/101

6s

6FMEA Template


83/101

6s

6

What is Hypothesis Testing ?


84/101

6s

Using Sample A and Sample B

to draw inferences about

population A and Population B

about Central Tendency and Variation.

Population A Population B

Sample A Sample B

Mean - A

Std. Dev - sA

Mean - B

Std. Dev - sB

Population Parameters

Mean - XA

Std. Dev - SA

Mean - XB

Std. Dev - SB

Sample Statistics

6sWhy Hypothesis Testing ?


85/101

61. Once we have identified these factors and made adjustments for improvement, we need to

validate actual improvements in our processes.

2. Sometimes we cannot decide graphically or by using calculated statistics (sample mean andstandard deviation) if there is a statistically significant difference between processes.

3. In such cases, the decision will be subjective.

4. We perform a formal statistical hypothesis test to decide objectively whether there is adifference.

6sHypothesis Testing to reduce Errors


86/101

Guilty, Sent to Jail

Innocent, Sent to Jail

(Suppliers Risk)

a Error

Guilty, Set Free

(Consumers Risk)

b ErrorInnocent, Set Free

GuiltyInnocent

Actuality

(of Population)

V

erdict/Inferenc

e

(FromS

ample) In

nocent

Gu

ilty

6sHypothesis Testing Protocol


87/101

1. The Null hypotheses are always statements about the population parameters

2. State your Null Hypothesis (Ho)Ho :The height of citizens in country A is greater than or equal to the

height of citizens in country B (A B).3. State your Alternative Hypothesis (Ha) , which is a negation of null hypothesis

Ha :The height of citizens in country A is less than the height of citizens

in country B (A < B).

4. Test Alternative Hypothesis with Statistical Test

5. Based on the test result, we reject or fail to reject the null hypothesis Ho

Reject Ho Accept Ho

0 0.05 1.00p

6sTypes of Hypothesis Tests


88/101

One-Sample Hypotheses

1. Ho : = constant = T

Ha : constant = T

2. Ho : s2 = constant

Ha : s2 constant



89/101

Two-Sample Hypotheses

3. Ho : 1 = 2

Ha : 1 2

4. Ho : 12Ha : 1 > 2

5. Ho : s12 = s2

2

Ha : s12 s2

2



90/101

Multi-Sample Hypotheses

6. Ho : 1 = 2 = . . . = n

Ha : at least one not equal

7. Ho : s12 = s2

2 = . . . = sn2

Ha : at least one not equal


91/101

6sSimple Regression Analysis


92/101

Test for Continuous Y Response and Independent Variable X (continuous)

6sImprove


93/101

Improve Phase Objectives

To develop a proposed solution

Identify an improvement strategy

Experiment to determine a solution

Quantify financial opportunities

To confirm that the proposed solution will meet or exceed the quality improvement goals

6sImprove


94/101

Objectives

To take action for eliminating main causes.

Prioritise action points, responsibility & time schedule.

Some Important Dos &Donts on Action Phase

1. Major Root Causes should be identified for countermeasures.

2. Be clear on the concept of Correction, Corrective Action & Preventive Action for all major RootCauses.

3. Check for feasibility of countermeasure (controllable v/s uncontrollable)

4. If controllable debate on touch points to decide team.

6sImproveImportant Dos and Donts


95/101

4. Check the priority of implementation of countermeasure and its impact.

5. Check the cost of countermeasure v/s impact.

6. Also check the timelines.

Hatched Area is ImmediatelyActionable Countermeasure

Medium

High

Low

CONTROL

LowHigh Medium

IMPACT

6sImproveImportant Dos and Donts


96/101

6. Get the actionable agreed on by sponsor of the area which is in question (Has the person und

erstood the action).

7. Check Point/Control Point should be build in the Action Plan.

8. Put responsibility for checking the review of action.

6sCONTROL


97/101

Deliverable:Measurement System is

Adequate to Measure Xs

Deliverable:Determine post-improvementcapability and Performance.

Confirm the improvementgoal has been realized

Deliverable:Develop and ImplementProcess Control Plan

Tools:Control charts

Mistake ProofingFMEA

6sControl Objectives


98/101

Processes will tend to degrade over time, losing the gains achieved by design and

improvement activities.

To make sure that our process stays in control after the solution has been implemented

To quickly detect the out-of-control state

To determine the associated special causes

To ensure that appropriate actions can taken to correct the problem before a defect is

produced

6sControl Mechanism


99/101

Various Control Mechanisms

Mistake Proofing

SPC

Avoid Potential

Problems

Control Potential

Problems

6sI&MR Chart


100/101

5040302010Subgroup 0

2.85

2.80

2.75IndividualValue

Mean=2.800

UCL=2.852

LCL=2.748

0.07

0.06

0.05

0.04

0.03

0.02

0.01

0.00Mo

vingRange

R=0.01958

UCL=0.06397

LCL=0

I and MR Chart for operator 1

6sX Bar and R Chart


101/101

0Subgroup 5 10 15

2.76

2.77

2.78

2.79

2.80

2.81

2.82

2.832.84

SampleMean

Mean=2.800

UCL=2.835

LCL=2.765

0.000.010.02

0.030.04

0.05

0.060.07

0.08

Sam

pleRange

R=0.01864

UCL=0.06091

LCL=0

Xbar/R Chart for operator 1

Understanding 6 Sigma

Documents