6 Sigma SD Shaft Dia. Variation

8/8/2019 6 Sigma SD Shaft Dia. Variation

1/32

SD BASKET SHAFT

DIAMETER VARIATION &

MWO DIMPAL HEIGHT VAR.

6


2/32

Commitment / Help Required

Six Sigma Theme Registration

App

rova

lVP MD

Deptt : Production

Theme

Period

Team Members

Theme

Description

Target

SD Basket Shaft Diameter Improvement

10/01/2000 - 20/03/2000

Sandeep Sethi, Sanjay Jain, AK Jindal

Project Schedule

Step

Event

Items

Time Schedule

Ist wk

1

2

3

4

M

A

I

C

Definition Of Yield

More Dia. Results In Tight Fitting Of SDBasket In Bellow Assembly,Displacing

The Spring OF Bellow,Causing Leakage

Through Spin Side. This Water Falls On

The Spin Motor , Leading To Burning Of

Motor.

From existing defect rate of

56,000 ppm to 3.4ppm.

Cost saving =Rs 75,000

RM Engg. ,the manufacturers of theS Shaft.

Shaft diameter

2nd wk 3rd wk 4th wk 5th wk 6th wk 7th wk 8th wk

Team Leader: Sanjay Arora

FacilitatorCustomer

HOD

Chetan

Khosla


3/32

Process Map 6

define measure analyse improve control

Parting

Turning

on lathe

Milling

Centre

Drill

Centre

less

Grinding

Knurling

Pressing

Insert

Rivet

Flaring ofRivet

Polishing

(oemery )

Final

Inspection

Sleeve

Insertion

Packing

Dispatch

to Brite

IQC at

brite

Moulding

Check for

runout

Dispatch to

LGEILaccepted

accepted

Scrap

rejected

IQC at

LGEIL

rejected

Segregation

Inspection

Emery

paper

Check

Sdbasket

assm.

a

cc

e

p

te

d

r

e

j

e

c

t

ed


4/32


5/32


6/32

ANALYSEANALYSE/Fish Bone Diagram 6

define controlanalyse

improvemeasure

Innovation with 6 Achieve Super A! LGEIL

Material

MethodMan

Method

Dia.

var.in

shaft

Min. cut possible

Manual feed

Not accounted for

Manufacturing

system Inspectionmethod

Position of shaftNo. of cuts

Depth of cut

Dressing of grinder

wheel

Inconsistent view of the

scale

Inconsistency in selecting

the point of checking

Inability to concentrate

Use of

wrong

measuring

system

Gages Micrometers


7/32

1 2

1 3 . 9 7 5

1 3 . 9 7 6

1 3 . 9 7 7

1 3 . 9 7 8

1 3 . 9 7 9

1 3 . 9 8 0

1 3 . 9 8 1

f a c t o r

dia.

ofshaft

B oxplots of d ia. of by fac tor

( m e a n s a re i n d i c a t e d b y so l i d c i r cl e s )

One-way Analysis of Variance

Analysis of Variance for dia. of

Source DF SS MS F Pfactor 1 0.0000528 0.0000528 77.13 0.000

Error 18 0.0000123 0.0000007

Total 19 0.0000651

Individual 95% CIs For

Mean

Based on Pooled StDev

Level N Mean StDev --------+---------+----

1 10 13.9765 0.0006

2 10 13.9797 0.0010

Pooled StDev = 0.0008 13.9770 13.9785

13.9800

ANALYSE / No. of cuts6

As p value is less than 0.05 so no. of cuts is a factor for

dia.variation in S - Shaft


Innovation with 6s AchieveSuperA

Level 1: 5 cuts

Level 2 : 6 cuts


8/32

ANALYSE / Measuring Sys.6

As p value is less than 0.05 so measuring system is a factor for

dia.variation in S - Shaft


Innovation with 6s AchieveSuperA

13.975

13.976

13.977

13.978

13.979

factor

dia.

Boxplots of dia. by factor

(means are indicated by sol id c i rc les)One-way Analysis of Variance

Analysis of Variance for dia.

Source DF SS MS F P

factor 1 0.0000153 0.0000153 28.05 0.000Error 18 0.0000098 0.0000005

Total 19 0.0000251

Individual 95% CIs For Mean

Based on Pooled StDev

Level N Mean StDev -+---------+---------+--

1 10 13.9777 0.0008 (---*--)

2 10 13.9759 0.0006 (--*--)

Pooled StDev = 0.0007 13.9755 13.9770 13.978513.9800

Level 1: mech.

Level 2: Digi.


9/32


10/32

No of cuts Measuring sy

5 6 mech

digi

13.9762

13.9774

13.9786

13.9798

13.9810

data

Main Effects Plot (data means) for data

No of cuts Mea.sys. data

6 mech 13.982

6 mech 13.983

6 mech 13.979

5 mech 13.977

5 digi 13.976

5 digi 13.975

6 digi 13.982

5 digi 13.975

5 mech 13.977

6 mech 13.982

6 digi 13.981

5 mech 13.977

6 digi 13.98

6 mech 13.979

5 mech 13.978

5 digi 13.975

6 digi 13.9795

6 digi 13.98

5 digi 13.976

5 mech 13.978

The graph suggests that no. of cuts is a

major factor & the measuring system

is a minor factor.

6define controlanalyseimprove

measure

IMPROVE /DOE


11/32

OPTIMUM CONDITIONS OF THE FACTORSOPTIMUM CONDITIONS OF THE FACTORS

OBTAINED AFTER DOEOBTAINED AFTER DOE

FACTORS OPTIMUM

CONDITIONS

1.NO. OF CUTS

2.MEASURING SYSTEM

3.DRESSING ( CUTTING WHEEL )

4.DRESSING ( CONTROL WHEEL )

SIX

DIGITAL MICROMETER

EVERY ONE HOUR

EVERY TWO DAYS


12/32

Innovations Practical Result

Improved the Process CapabilityTo more than Six Sigma level.

all Operators about the seriousness ofEducated Vendor Top Management &

quality of this dimension and also how

to maintain it.

Provided the right equipment &educated the vendor supervisor &operators about how to use theequipment.

Involved the Vendor supervisors indeveloping the control mechanism &plan as well as its execution.

Four Vendor persons and one LGperson involved in 100 % inspectionremoved.

Avery tight tolerance of 11microns(10

-6m) earlier thought unachievable

was met. A Chronic problem of Washing

machine line : SD Shaft loose or tightwas solved.

Leakage problem on the line due toscratches generated because of excessivehandling was also eliminated.

Total RTN reduced from 56000 toZero .

Three stages of emery paper rubbing ,rejection from Brite IQC and

Segregation at our end were eliminated.

Innovation with 6 Achieve Super A! LGEIL

ANALYSEANALYSE/Fish Bone Diagram 6

define controlanalyse

improvemeasure


13/32

1 3 .9 7 5 1 3 .9 7 7 1 3 .9 7 9 1 3 .9 8 1 1 3 .9 8 3 1 3 .9 8 5 1 3 .9 8 7

L S L U S L

P r o c e s s C a p a b i l i t y A n a ly s i s f o r d i a m

U S L

T a r g e t

L S L

M e a n

S a m p l e NS t D e v ( S T )

S t D e v ( L T )

C p

C P U

C P L

C p k

C p m

P p

P P U

P P L

P p k

P P M < L S L

P P M > U S L

P P M T o ta l

P P M < L S L

P P M > U S L

P P M T o ta l

P P M < L S L

P P M > U S L

P P M T o ta l

1 3 . 9 8 6 0

*

1 3 . 9 7 5 0

1 3 . 9 8 0 0

3 00 . 0 0 0 7 5 7 9

0 . 0 0 1 0 1 1 7

2 . 4 2

2 . 6 2

2 . 2 2

2 . 2 2

*

1 . 8 1

1 . 9 6

1 . 6 6

1 . 6 6

0 . 0 0

0 . 0 0

0 . 0 0

0 . 0 0

0 . 0 0

0 . 0 0

0 . 3 0

0 . 0 0

0 . 3 0

P r o c e s s D a t a

P o t e n t i a l ( S T ) C a p a b i l i ty

O v e r a l l ( L T ) C a p a b i l i ty O b s e r v e d P e r f o r m a n c e E x p e c t e d S T P e r fo r m a n c eE x p e c t e d LT P e r f o r m

S T

L T

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

L S L U S L

P r o c e s s C a p a b i l i t y A n a ly s i s f o r d i a m

C a l c u l a ti o n s B a s e d o n W e i b u l l D i s t r i b u t i o n

U S L

T a r g e t

L S L

M e a n

S a m p le N

S h a p e

S c a l e

P p

P P U

P P L

P p k

P P M < L S L

P P M > U S L

P P M T o t a l

P P M < L S L

P P M > U S L

P P M T o t a l

1 3 . 9 8 6 0

*

1 3 . 9 7 5 0

1 3 . 9 7 6 0

3 0

1 7 6 9 2 . 1

1 4 . 0

1 . 6 4

2 . 4 0

0 . 3 6

0 . 3 6

0 . 0 0

0 . 0 0

0 . 0 0

1 3 9 1 9 0 . 5 5

0 . 0 0

1 3 9 1 9 0 . 5 5


O v e r a l l ( L T ) C a p a b i l i ty

O b s e r v e d L T P e r f o r m a n c e

E x p e c t e d L T P e r f o r m a n c e

BEFORE6Cp = 1.5Cpk=0.36

Cp = 2.42Cpk=2.12

ImproveImprove/Process Capability definemeasure analyse improve control

AFTER6

6


14/32

1Subgroup 2 3 4 5 6

13.9785

13.9795

13.9805

13.9815

SampleMean

X=13.98

3.0SL=13.98

-3.0SL=13.98

0.000

0.001

0.0020.003

0.004

0.005

SampleR

ange

R=0.002353

3.0SL=0.00497

-3.0SL=0.00E+

Xbar/R Chart for diameter

ControlControl /Xbar R Chart 6


15/32

Date 1 2 3 4 5 6 7 8 9 1012 13 14 15

X1

X2

X3

X4

X5

13.9860

13.9815

Remarks

Total X

Average x

Range R

X Chart

0.00

5

0.00

4

0.00

3

0.002

0.00

R Chart

In ChargeSupervisorX-R Control Chart(S Shaft Diameter)

CTQ No.

IQC -02

Part Name

Measuring Unit

Measuring Method

S SHAFT( SD Basket)

mm

Digital Micrometer

Spec.

Spec.Limit

UpperLower

Periodical Check

14.000-0.014-0.025

13.98613.975

Model

Application

Time period

All Washing Machines

W/M Assembly Line

01/03/2000~15/03/2000

CheckedBy

Cpk

MeasuredValue

Every 2hours

13.9785

13.9750

13.980


16/32

CTP (Check Sheet)CTQ

S Shaft (SD Basket ) 8003

LINE

IQC

CTP No.

IQC-02-01

CTP Item

No. of cuts

How to checkSpec. Frequency

Every 2 Hours

Remarks

Date

Month ( )

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 2

9:00

Measuring SystemIQC-02-02

IQC-02-03

6Digital

Grinding Wheel Every HourDressing

Every 2 Hours

IQC-02-04 Control Wheel Dressing Update W.I After 2 days

11:00

2:00

5:00

11:00

2:00

5:00

9:00

10.00

9:00

CTP Name

No. of Cuts

MeasuringSystem

Cuting Wheel

Update W.I

Update W.I

UpdateW.I

11.0012.003:004:005:00

ControlWheel

2 days

Signature of


17/32

0

10000

20000

30000

40000

50000

60000

Jan Feb Mar Apr May

REJECTION

6 SIGMALEVEL

ZeroRejectionR

eje

ctIon

56k

22k

0.1k


18/32

0

10000

20000

30000

40000

50000

60000

Jan Feb Mar Apr May

REJECTION

6 SIGMALEVEL

38 k

62 k 63 k 63 k

ZeroRejection

ANNUAL SAVING = 6.27

LACS

Reje

ctIon


19/32

CTQ Registration Format. 6

CTQ Description(what is the CTQ)

CTQ REGISTRATIONCTQ REGISTRATION( SD Shaft Dia Variation)( SD Shaft Dia Variation)

Zst

Zlt

Target Present

Registration No.

Date

Graphical Description (show sketch or photo)

Measuring System(How to measure)

Sig

n

PjtLdr. Super A CTQ

InchargeR&D QP

Gage R&R Specifications Control Limits

%Study

Variation% Tolerance LSL USL LCL UCL

CTP List Document Check List

S.No. Name Area ofApplication

CTP Spec. S.No. Document

!Doc. Reference

Number

Shaft Diameter Digital Micrometer ( LC-0.001 mm)

29.63% 10.47% 13.9750mm

13.9860mm

13.9785mm

13.9815mm

7.26

6.36

1

2

3

4

Number if cuts

Measuring sys

Grinding Wheel

Control Wheel

Vendor end

Vendor end

Vendor end

Vendor end

6

Digital

Dressing everyhour

Dressing every2 days

6.0

4.5

SDShaft

Approvald


20/32

Theme Registration66Approval

Pjt. Leader

Guide

Dept. Head

V.P.

M.D.

Period

18 NOV.99

to

17 FEB .00

Name Sign

MEMBERS

Theme :Theme :

Detailed Description :Detailed Description :

Q.Fn.(Y) Specification Gauge Name Gauge L.C. Current ( Y ) Target ( Y )

Process Map With Yield of each processProcess Map With Yield of each process Logic Tree of Worst ProcessLogic Tree of Worst Process

Request To M.D.Request To M.D.Estimated Contribution after Project

Qualitative Quantitative (Rs. Lacs)

Sanjay Arora

C. Khosla

A.K.Jindal

H.G.Choi

N.C.Upreti

V.Madaan

NO. OF

SET UP REJ. NIL NILNIL 80,000 PPM 3.4 PPM

OPTIMISING SET UP COND FOR PROJ. WELDING

FOR MS-283/304 MWO CAVITY.

* HIGH REJECTION DUE TO UN OPTIMISED SET UP CONDITIONS.

* THE LOSS IS APPROX RS.400 PER CAVITY.

* IT IS A CTQ AS IF THE Pcs GO UNDETECTED THESE CAN LEAD

TO FAILURE OF THE M/C & HAMPER MARKET POSITION.

Inspection

of sheetsU-Bending

Back Short

Welding

Fr. Short

Welding

TT Bkt

Welding

Balance

Checking

Wv Gd/Mgt

Welding

Lo-Up

Welding

Back Long

WeldingFr. Long

Welding

Hng. Plt

Welding

Shift To

MW Line

Set Up Rej.

of MS-283/304

Welding

Pressure

Welding

Current

Dimple

Height

Contact

Time

Sheet

Chemistry

Rs. 400,000* Improvement inRejection

Measure


21/32

6DefineMeasure

Analyse Improve ControlMeasure / Gage R&R

LG ElectronicsInnovation with Achieve Super A! 6

StdDev Study Var %Study Var %Tolerance

Source (SD) (5.15*SD) (%SV) (SV/Toler)

Total Gage R&R 1.36E-03 0.006997 6.44 5.60

Repeatability 1.34E-03 0.006878 6.33 5.50

Reproducibility 2.49E-04 0.001283 1.18 1.03Operator 2.49E-04 0.001283 1.18 1.03

Part-To-Part 2.11E-02 0.108451 99.79 86.76

Total Variation 2.11E-02 0.108677 100.00 86.94

Number of Distinct Categories = 22

Gage Used For Measurement of Dimple Height : Puppy Dial

Least Count= 0.001 mm

As Gage R&R % Study Variation & % Tolerance is less than 20% hence we can use this gage for dimple height

variation study

Sample Jindal Jindal2 V .M adaan V.Madaan2

1 1.295 1.293 1.295 1.292

2 1.299 1.299 1.299 1.299

3 1.289 1.29 1.284 1.287

4 1.322 1.322 1.322 1.322

5 1.305 1.3 1.302 1.305

6 1.279 1.279 1.279 1.279

7 1.298 1.3 1.298 1.298

8 1.302 1.302 1.302 1.302

9 1.348 1.348 1.348 1.348

10 1.333 1.33 1.33 1.331

Measure


22/32

6DefineMeasure

Analyse Improve ControlMeasure / Gage R&R


1 .1 5 1 .2 0 1 .2 5 1 .3 0 1 .3 5 1 .4 0

L S L U S L

D i m p l e H t.P r o c e s s C a p a b i li ty A n a l ys i s f o r

U S L

T a rg e t

L S L

M e a n

S a m p l e N

S t D e v ( W i t h i n)

S tD e v (O v e ra l l )

C p

C P U

C P L

C p k

C p m

P p

P P U

P P L

P p k

P P M < L S L

P P M > U S L

P P M T o ta l

P P M < L S L

P P M > U S L

P P M T o ta l

P P M < L S L

P P M > U S L

P P M T o ta l

1 . 3 7 5 0 0

*

1 . 2 2 5 0 0

1 . 2 9 0 4 4

1 25

0 . 0 2 5 8 1 6 4

0 . 0 4 2 1 1 3 7

0 .9 7

1 .0 9

0 .8 4

0 .8 4

*

0 .5 9

0 .6 7

0 .5 2

0 .5 2

4 0 0 0 0 . 0 0

4 0 0 0 0 . 0 0

8 0 0 0 0 . 0 0

5 6 2 4 . 1 2

5 2 7 . 6 1

6 1 5 1 . 7 3

6 0 1 0 0 . 5 6

2 2 3 2 9 . 1 6

8 2 4 2 9 . 7 2


P o te n t i a l (W i th i n ) C a p a b i l i t y

O v era ll C ap ab il ity O bs e rv e d P e rfo rm a nc e E x p . "W i th in " P e rf orm a nc e E x p . "Ov e ra ll " P e rfo rm a n

W i thin

Ov e ra l l

Four Block Diagram

A B

C D

Zst

Zshift

1.5

4.5

From measurement of dimple Ht. ; which we know is an important factor for quality of welding

we know that it is a primarily a problem of variation.

6Analyse


23/32

Set Up

Rejection

Machine

Method

Man


VOLTAGELEVELPRESSURE

ELECTRODES GAPELECTRODES

DRESSING

CAVITY TPR

DURING WELDING

PARAMETERS

NOT DEFINED PROPERLY

Material

DIMPLE HEIGHT

VARIATION

PROFILEOF

DIMPLE CONTACT

TIME

SHEET

CHEMISTRY

6Define MeasureAnalyse

Improve ControlAnalyse / 4-M Diagram

6Measure


24/32

Sheet

Sheet

DIMPLE WITH CONICAL PROFILE

DIMPLE WITH TOMB PROFILE


6DefineMeasure

Analyse Improve ControlAnalyse / Dimple Profile

Two proportion test to examine the effect of dimple profile on no. of weak joints during

projection welding.

Test and CI for Two Proportions

Sample X N Sample p

Tomb Type 3 42 0.071429

Conical 13 42 0.309524

Estimate for p(1) - p(2): -0.238095

95% upper bound for p(1) - p(2): -0.103783

Test for p(1) - p(2) = 0 (vs < 0): Z =

-2.92

P-Value = 0.002

We have established that the dimple profile is having an effect on welding quality.Tomb

profile is better.

6Analyse

A l / Di l P fil


25/32


6Define MeasureAnalyse

Improve ControlAnalyse / Dimple Profile

1.381.361.341.321.301.281.261.241.22

U SLL S L

P r o c e s s C a p a b i l i ty A n a l y s i s fo r C 4 5

P P M T o ta l

P P M > U S L

P P M < L S L

P P M T o t al

P P M > U S L

P P M < L S L

P P M T ot a l

P P M > U S L

P P M < LS L

P pk

P P L

P P U

P p

C pm

C pk

C P L

C P U

C p

S tD e v (Ove ra l l)

S tD e v (W i th in )

S a m p l e N

Me a n

LS L

TargetU S L

8.68

0.42

8.25

0.00

0.00

0.00

0.00

0.00

0.00

1.44

1.44

1.64

1.54

*

2.45

2.45

2.81

2.63

0.0162463

0.0095059

12 5

1.29498

1.22500

*1.37500

E xp. "Overa l l " P erformancE xp . " Wi th i n " Pe r fo rma n ceOb se rve d P e r fo rma n ceOve ra l l C a p a b i li t y

P otentia l (W i th in) Capabi l i ty

P ro ce ss D a ta

W ith in

O v e r a l l

1 .1 5 1 .2 0 1 .2 5 1 .3 0 1 .3 5 1 .4 0

L S L U S L

D i m p l e H t.P r o c e s s C a p a b i li ty A n a l ys i s fo r

U S LT a rg e t

L S L

M e a n

S a m p l e N

S t D e v ( W i t h i n )

S tD e v (O v e ra l l )

C p

C P U

C P LC p k

C p m

P p

P P U

P P L

P p k

P P M < L S L

P P M > U S L

P P M T o t a l

P P M < L S L

P P M > U S L

P P M T o ta l

P P M < L S L

P P M > U S L

P P M T o ta l

1 . 3 7 5 0 0*

1 . 2 2 5 0 0

1 . 2 9 0 4 4

1 2 5

0 . 0 2 5 8 1 6 4

0 . 0 4 2 1 1 3 7

0 .9 7

1 .0 9

0 .8 40 .8 4

*

0 .5 9

0 .6 7

0 .5 2

0 .5 2

4 0 0 0 0 . 0 0

4 0 0 0 0 . 0 0

8 0 0 0 0 . 0 0

5 6 2 4 . 1 2

5 2 7 . 6 1

6 1 5 1 . 7 3

6 0 1 0 0 . 5 6

2 2 3 2 9 . 1 6

8 2 4 2 9 . 7 2


P o te n t i a l (W i th i n ) C a p a b i l i t y

O v era ll Ca pa b il it y O bs e rv e d P e rfo rm a nc e E x p . "W i th in " P e rf orm a nc e E x p . "O ve ra ll " P e rfo rm a n

W i thin

Ov e ra l l

The press die dimple profiles were changed as per previous test inference. Also the punches

which were varying in height were made same.With this direct improvement the process

capability of dimple height improved from 0.97 to 2.63.

6

I / SS C it


26/32

PG PSP voltage O.K N.G. Response(%o.k)

3.000 1.000 270 2 10 0.167

4.500 1.000 270 1 11 0.083

3.000 1.500 270 4 9 0.308

4.500 1.500 270 0 13 0.000

3.000 1.000 320 11 1 0.917

4.500 1.000 320 2 10 0.167

3.000 1.500 320 11 2 0.846

4.500 1.500 320 6 7 0.462

3.750 1.250 295 4 8 0.333

3.750 1.250 295 8 5 0.615

3.750 1.250 295 3 9 0.250

3.750 1.250 295 7 6 0.538

2.525 1.250 295 11 1 0.917

4.975 1.250 295 5 8 0.385

3.750 0.842 295 4 8 0.333

3.750 1.658 295 5 8 0.385

3.750 1.250 254 2 10 0.167

3.750 1.250 336 8 5 0.615

Response Surface Regression: r versus PG, voltageThe analysis was done using coded units.

Estimated Regression Coefficients for r

Term Coef SE Coef T P

Constant 0.4285 0.04016 10.671 0.000

Block -0.0383 0.04016 -0.955 0.356

PG -0.1796 0.04399 -4.082 0.001

voltage 0.1925 0.04399 4.375 0.001

S = 0.1606 R-Sq = 72.4%R-Sq(adj) = 66.5%

Analysis of Variance for r

Source DF Seq SS Adj SS Adj MS F P

Blocks 1 0.02351 0.02351 0.02351 0.91 0.356

Regression 2 0.92387 0.92387 0.46194 17.90 0.000

Linear 2 0.92387 0.92387 0.46194 17.90 0.000

Residual Error 14 0.36127 0.36127 0.02581

Lack-of-Fit 6 0.21210 0.21210 0.03535 1.90 0.198

Pure Error 8 0.14918 0.14918 0.01865

Total 17 1.30866


6Define Measure Analyse Improve ControlImprove / SS CavityWe know from past setting experience that three parameters (PG - Pressure Gauge. PSP &

Voltage ) have a crucial impact on welding quality. We did RSM to establish the best machine

condition.

After Analysis of RSM model , we realise that PSP is not a vital few factor and hence is

removed from the regression equation.

I / SS C it (Wi f Pl t) 6Improve


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0.0

0.5r

34PG

3

1.0

270260

5

250

330320

310300

290

voltage280270260

340330

voltage

Surface Plot of r ( %age O.K.)


Improve / SS Cavity (Wireframe Plot)

Best Condition :

Voltage :310

PG :2.8

By the Wire Frame plot we establish the best condition for SS-cavity

6Define Measure AnalyseImprove

Control

I / G S C it 6

Improve


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voltpsppg

320

270

1 .51 .04 .53.0

0.24

0.18

0.12

0.06

0.00

resp

Main Effects Plot (data means) for resp

320

270

1.51

0.30

0.15

0.00

0.30

0.15

0.00

pg

psp

volt

1.5

1

4.5

3

Interaction Plot (data means) for resp

p g p s p v o l t o k r e j r e s p

3 .0 0 1 .0 0 2 7 0 . 0 03 . 0 0 9 . 0 0 0 . 2 5

4 .5 0 1 .0 0 2 7 0 . 0 00 .0 0 1 3 .0 0 0 .0 0

3 .0 0 1 .5 0 2 7 0 . 0 04 . 0 0 8 . 0 0 0 . 3 34 .5 0 1 .5 0 2 7 0 . 0 00 .0 0 1 3 .0 0 0 .0 0

3 .0 0 1 .0 0 3 2 0 . 0 00 .0 0 1 3 .0 0 0 .0 0

4 .5 0 1 .0 0 3 2 0 . 0 00 .0 0 1 2 .0 0 0 .0 0

3 .0 0 1 .5 0 3 2 0 . 0 05 . 0 0 8 . 0 0 0 . 3 84 .5 0 1 .5 0 3 2 0 . 0 00 .0 0 1 3 .0 0 0 .0 0


Improve / GpSp Cavity 6Define Measure AnalyseImprove

Control

We know from past setting experience that three parameters (PG - Pressure Gauge. PSP &

Voltage ) have a crucial impact on welding quality. We did 2 level factorial design to establish the

vital few.

We conclude that PG & PSP seem to have more effect than voltage in this case.There is

also mild interaction between all factors.

I / G S C it 6

Improve


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Response Surface Regression: resp versus pg, psp

The analysis was done using coded units.

Estimated Regression Coefficients for resp

Term Coef SE Coef T P

Constant 0.0309 0.03810 0.812 0.432

Block -0.0368 0.02865 -1.284 0.222

pg -0.1856 0.03113 -5.963 0.000

psp 0.0634 0.03113 2.035 0.063

pg*pg 0.1402 0.03262 4.298 0.001

S = 0.1137 R-Sq = 82.6% R-Sq(adj) = 77.2%

Analysis of Variance for resp

Source DF Seq SS Adj SS Adj MS F P

Blocks 1 0.043849 0.021291 0.021291 1.65 0.222

Regression 3 0.751804 0.751804 0.250601 19.39 0.000

Linear 2 0.513070 0.513070 0.256535 19.85 0.000Square 1 0.238735 0.238735 0.238735 18.47 0.001

Residual Error 13 0.168013 0.168013 0.012924

Lack-of-Fit 5 0.130239 0.130239 0.026048 5.52 0.017

Pure Error 8 0.037773 0.037773 0.004722

Total 17 0.963666

pg psp volts ok rej resp

3.00 1.00 270 3 9 0.250

4.50 1.00 270 0 13 0.000

3.00 1.50 270 4 8 0.333

4.50 1.50 270 0 13 0.000

3.00 1.00 320 0 13 0.000

4.50 1.00 320 0 12 0.0003.00 1.50 320 5 8 0.385

4.50 1.50 320 0 13 0.000

3.75 1.25 295 1 11 0.083

3.75 1.25 295 0 13 0.000

3.75 1.25 295 0 12 0.000

3.75 1.25 295 0 13 0.000

2.53 1.25 295 12 1 0.923

4.97 1.25 295 0 12 0.000

3.75 0.84 295 0 13 0.000

3.75 1.66 295 3 10 0.231

3.75 1.25 254 0 12 0.000

3.75 1.25 336 0 13 0.000



Control

We have done RSM to optimise the welding machine settings for GpSp cavity.We have used the

Central composite design.

We conclude that the main effect is of PG(Pressure gauge) & PSP has some effect.But

voltage which was very important in SS case is not important in GpSp.

Impro e / GpSp Ca it 6Improve


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0.0

0.5

resp

34

pg3

1.0

1.00.9

5

0.8

1.51.41.31.2 psp1.1

1.00.9

1.71.6

1.5

psp



Control

Best Condition :

PSP :1.3

PG :2.8

Through Wire frame plot we establish the best condition for GpSp Cavity.


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Rejection Trend 6


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Rejection Trend 6Define Measure Analyse Improve Control

0

20000

40000

60000

80000

November

January

M

arch

May

July

PPM

PPM

6 Project

Documents

6 Sigma SD Shaft Dia. Variation