contoh kasus six sigma dipublikasi oleh

(1)

A R I P I N

2002 - 21 – 140

TEKNIK INDUSTRI

UNIVERSITAS INDONUSA ESA UNGGUL

2004

MENURUNKAN CACAT NO POWER PADA PRODUKSI

TV

DENGAN METODA SIX SIGMA

DI PT LG ELECTRONICS INDONESIA

MENURUNKAN CACAT NO POWER PADA PRODUKSI

TV

DENGAN METODA SIX SIGMA

DI PT LG ELECTRONICS INDONESIA

MENURUNKAN CACAT NO POWER PADA PRODUKSI

TV

(2)



_{Makin bertambah nilai sigma,}

makin berkurang biaya kualitas dan waktu siklus



_{Sigma adalah ukuran satuan statistik yang menggambarkan}

kemampuan suatu proses dan ukuran nilai sigma dinyatakan dalam

DPU (Defect Per Unit) atau PPM



_{Dapat dikatakan bahwa proses dengan nilai sigma lebih tinggi}

dalam proses akan mempunyai cacat yang lebih sedikit

Konsep Six Sigma



_{Six Sigma : Suatu sistem yang flexibel untuk memperbaiki kinerja}

yang mendukung sukses secara terus-menerus.



_{Six Sigma dibangun berdasarkan banyak ide manajemen yang penting dan}

(3)

Menggunakan Z sebagai satuan ukuran kemampuan proses



_{Bila keragaman / variasi turun, maka}

kemungkinan cacat juga turun,

maka kemampuan (capability)

meningkat

Kemampuan 6s

1σ

• Z = 3

2σ 3σ

Kemampuan 3s

USL LSL

• Z = 6

1σ 2σ 3σ 4σ 5σ 6σ



= s =

( Xi- X )

2



i = 1 n

n - 1

Sample’s standard deviation :



=

X

=

Xi



i = 1 n

n

Sample’s average :

Z

=



x -



(4)

DEFINE

MEASURE

ANALYZE

IMPROVE

CONTROL

•Identify Customer’s CTQ

•Develop a team charter

•Defne and build a process

map

•Validate problem

/ process

•Measure key

problem

•Current

condition

•Screening potential

factor

•Identify vital few root

causes

•Validate hypothesis

•Develop ideas to cut

of root causes

•Optimation solution

•Measure solution

•Standardize

solution

•Establish standard

measure to

maintain

performance

(5)

μ

USL USL

T

Tepat namun tidak akurat

Geser

menuju

Target

Turunkan

Variasi

μ

USL USL

T

Shifting/bergeser ke Target & Mereduksi Variasi

Object

dari 6

adalah

Shift(geser) ke target

Menurunkan Variasi

Konsep Six Sigma

USL USL

T

μ

(6)

Aplikasi detail Six Sigma

Perbaikan dengan Metoda Six Sigma ( DMAIC )

(7)

REDUCE SMPS TRANSFORMER

SHORT ( NO POWER )

REDUCE SMPS TRANSFORMER

SHORT ( NO POWER )

2004 06 14

Incoming Quality Control

(8)

Project Registration Sheet

Current

Target

Improvement_{Ratio (%)}

0 PPM

Role

Dept

Telp.

Name

February 3 ~ 6, 2004

February 9 ~ 21, 2004

February 24 ~ 28, 2004

March ~ May, 2004

REDUCE SMPS TRANSFORMER

SHORT ( NO POWER )

Short Test as check point at line

production of Samwha and IQC LGEIN.

Good reliability part

WIRE HOLE

WIRING CROSS

CHECKING PROSSES

Aripin

QA

212 • Material Checking method

• Quality System set up

(9)

Problem Situation

Management policy said we have reduce field claim.

Data field claim show No Power is cause biggest

than other.

No power is TV Set have no supply voltage. It show by not light ofIndicator power and no display on tube.

No power can caused by parts, like power cord, SMPS Transformer, IC, FBT, Transistor and others.

SMPS Transformer have function as divider power voltage to several sub circuit or part like FBT, IC, and others.

If SMPS not function, it can’t supply voltage to parts or sub circuit

.

840 PPM

Defect Analysis by No Power

5 WORST SYMPTOM IN 2003

No Power

Data field claim 2003

29%

Defect Analysis by Model

(10)

Improve TV Quality

Attribute 30% SCR Reducing Improve TV Quality

Attribute

Big Y

Little y2

Bad SystemConnector

AGC Circuit

FrontCabinet Dented PWB Short Bad Wiring Connection

LoosenPart

Opt. Skill, Ability Wire Connection

Handling Handling Opt. Skill, Ability Wrong Connection

Handling AGC Circuit Opt. Skill, Ability

No connection How to Use How to used Plug Connection

Environment

Chassis Reliability

Screen Focus, DYC,PRT ABL Short AGC, No Ruster No Sound Problem

No Power Un Connect

Reliability

1P1P IQC Finished

Theme Selection

(11)

Process Mapping

LGEIN LQC

• PatrolPatrol

• PerformancePerformance

Final

Inspect

SAMWHA

Process

•R&DR&D

• PurchasePurchase

•IQCIQC

•ProductionProduction

• LQCLQC

• OQCOQC

LGEIN OQC

• ELTELT

• LTLTLTLT

•Reliability Reliability Product

Product

LGEIN IQC

• AppearanceAppearance

• DimensionDimension

•StructureStructure

•PerformancePerformance

• AssemblingAssembling

• Reliable PartReliable Part

High defect

SMPS no power

At LGEIN production

Selecting Best

Condition

for reliable Part

Find Out what is

the Main Cause of

Problem

• OS&D

(12)

SMPS

Component :

• Core

• Bobbin

• Wire

• Insulation

• Tape

• Shield

SMPS

What is SMPS Transformer ?

7

5

1

2 9

8

10

14

12 13

Output of SMPS (Voltage)

• Pin 9 - 8 : 24 ~ 25

• Pin 10 - 11 : 10 ~ 12

• Pin 14 - 13 : 110 ~ 115

• Pin 13 - 12 : 13 ~ 14

• Pin 1 – 2 : 7 ~ 10

Potential Short

Area

Short can be happen if one of wire on potential area

get direct connect.

(13)

Clarification Of Y

Indicator

Display

TV Set Power OK TV Set No Power

No Power

SMPS

DEFECT

APPEARANCE

DIMENSION

PERFORMANCE

MARKING NG

RUST

ISOLATION NG

P/P OVER

WIRE SHORT

BROKEN

TURNS

Kind of defect by SMPS

Master Signal

Test Signal

Master Signal= Test Signal

NG SIGNAL DISPLAY OK SIGNAL DISPLAY

SMPS Transformer Characteristic

Display of Surge Comparison Tester ( ST-215 ) will

show two signal both master and part test.

If form signal different that’s part NG

and if same is OK

.

Demonstration of Data gathering

(14)

Measurement (

Gage R&R)

Date of study : JANUA RY 15. 2004 Reported by : ARIPIN Name of product: SHORT TEST Misc:

Assessment Agreement

Within Appraisers Appraiser vs Standard

Assessment Agreement : 100 %



Operator is good in inspection



Instrument is valid and reliable

Measurement System are

Acceptable

Instrument : Surge Comparison Tester ( ST-215 )

Agreement Analysis

Within Appraisers :

Appraiser agrees with himself across trial

Appraiser # Inspected # Matched Percent 95 % CI OPR-1 25 25 100.00 (86.09, 100.00) OPR-2 25 25 100.00 (86.09, 100.00) OPR-3 25 25 100.00 (86.09, 100.00)

Each Appraiser vs Standard :

Appraiser's assessment across trials agrees with the known standard

Appraiser # Inspected # Matched Percent 95 % CI OPR-1 25 25 100.00 (86.09, 100.00) OPR-2 25 25 100.00 (86.09, 100.00) OPR-3 25 25 100.00 (86.09, 100.00) Between Appraisers :

All appraisers' assessments agree with each other. Assessment Agreement

# Inspected # Matched Percent 95 % CI 25 25 100.00 (86.09, 100.00)

Sample Attribute Try 1 Try 2 Try 1 Try 2 Try 1 Try 2 1 Pass Pass Pass Pass Pass Pass Pass 2 Pass Pass Pass Pass Pass Pass Pass 3 Pass Pass Pass Pass Pass Pass Pass 4 Fail Fail Fail Fail Fail Fail Fail

21 Fail Fail Fail Fail Fail Fail Fail 22 Pass Pass Pass Pass Pass Pass Pass 23 Pass Pass Pass Pass Pass Pass Pass 24 Fail Fail Fail Fail Fail Fail Fail 25 Fail Fail Fail Fail Fail Fail Fail Known Population OPR 1 OPR 2 OPR 3

(15)

Capability Process (Current)

Based on data October ~ December ‘03, defect SMPS 124 ea from 147595 ea.

• Defect Op. = 1 ( Wire Short )

• DPU = 124 : 147595

• DPO = 124 : ( 147595 x 1 ) = 8.4E-04

• DPMO = DPO x 1.000.000 = 840 PPM

From Z Normal table, we get :

DPO = 8.4E-04

Z Value = 3.1 + 0.04

= 3.14

Our Condition now :

Sigma level

= 3.14+ 1.5

=

4.64 

8.45E-04

3.1

0.04

(16)

Estimate Cause Analysis

By Analyzing all potential problem that could have significant effect for SMPS Performance,

thru

Brainstorming

and screening

, we succeed to collect some root cause for the problem

Material

Method

wire

Hole

Space

Finishing

Core

Turn wiring

Home pin

Varnish

Dielectric Breakdown

Press

Short (No Power)

Potential Factor

(17)

Selecting Vital Factor

Test and CI for Two Proportions

Sample X N Sample p 1 0 25 0.000000 2 19 25 0.760000 Difference = p (1) - p (2) Estimate for difference: -0.76

95% CI for difference: (-0.927414, -0.592586) Test for difference = 0 (vs not = 0): Z = -8.90

P-Value = 0.000

-

Since P-Value < 0.05, Reject Ho

-

It’s mean that

Dielectric breakdown

has an effect or SMPS reliability.

Dielectric Breakdown is

Vital Few factor

X

1 = Dielectric Breakdown

Hypothesis Testing

Ho : P P 2 ( There are no different Proportion Between D/B below 2250 V and D/B above 2250 V)

Ho :

P

≠

P

 ( There are different Proportion Between D/B below 2250 V and above 2250 V)

Sample 2250 Decision Sample 2250 Decision

1 2235 FAIL 14 1850 FAIL 2 1990 FAIL 15 2230 FAIL 3 2010 FAIL 16 1990 FAIL 4 2240 FAIL 17 2010 FAIL 5 2125 FAIL 18 1890 FAIL 6 2150 FAIL 19 2110 FAIL 7 2250 FAIL 20 2225 FAIL 8 1990 FAIL 21 2000 FAIL 9 2000 FAIL 22 2010 FAIL 10 2230 FAIL 23 1995 FAIL 11 2000 FAIL 24 1890 FAIL 12 1985 FAIL 25 1885 FAIL 13 1960 FAIL

D/B : 2250 V

Sample 2250 Decision Sample 2250 Decision

1 5430 PASS 14 4300 PASS 2 4795 PASS 15 5800 PASS 3 4500 FAIL 16 7800 FAIL 4 5350 PASS 17 7900 PASS 5 6000 FAIL 18 4600 FAIL 6 5100 PASS 19 5800 PASS 7 5700 PASS 20 5500 PASS 8 5700 PASS 21 7500 PASS 9 4500 PASS 22 7900 PASS 10 5000 PASS 23 5600 PASS 11 4100 PASS 24 4500 FAIL 12 4250 FAIL 25 6500 PASS 13 5600 PASS

D/B : 2250 V

(18)

Selecting Vital Factor

Sample X N Sample p 1 25 25 1.000000 2 14 25 0.560000 Difference = p (1) - p (2) Estimate for difference: 0.44

95% CI for difference: (0.245420, 0.634580) Test for difference = 0 (vs not = 0):

Z = 3.76

P-Value = 0.000

-

Since P-Value < 0.05, Reject Ho

-

It’s mean that

Pin Hole Wire

has an effect or SMPS reliability.

Pin Hole Wire is

Vital Few factor

X

2 = Pin Hole Wire

Hypothesis Testing

Ho : P P 2 ( There are no different Proportion Between Pin Hole Below 5 and Above 5)

Ho :

P

≠

P

 ( There are different Proportion Between Pin Hole Below 5 and Above 5)

Sample 5 Decision Sample 5 Decision

1 0 PASS 14 1 PASS

Sample 5 Decision Sample 5 Decision

(19)

Sample Varnish Decision Sample Varnish Decision

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

Sample Non Vr. Decision Sample Non Vr. Decision

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

X3 = Pressure

Hypothesis Testing

H0 :

P 1 = P

2 (

There are no different Proportion Between varnish and no varnish )

H1 :

P 1 ≠ P 2 (There are different Proportion Between varnish and no varnish )

Varnish

No Varnish

Sample X N Sample p 1 22 25 0.880000 2 21 25 0.840000 Difference = p (1) - p (2) Estimate for difference: 0.04

95% CI for difference: (-0.152036, 0.232036) Test for difference = 0 (vs not = 0):

Z = 0.41

P-Value = 0.683

P Value > 0.05, Receive H0,

Varnish

not significant as Vital Factor

.

13 - 22

(20)

Sample Space Decision Sample Space Decision

Sample No Space Decision Sample No Space Decision

1 NS PASS 14 NS PASS

No Space _Space

No Space

Space

P Value > 0.05, Receive H0

,

Space not significant as Vital Factor

.

Sample X N Sample p 1 22 25 0.880000 2 24 25 0.960000 Difference = p (1) - p (2)

Estimate for difference: - 0.08

95% CI for difference: (-0.152036, 0.232036) Test for difference = 0 (vs not = 0):

Z = 0.41

P-Value = 0.297

14 - 22

(21)

Sample Cross Decision Sample Cross Decision

Analyzing Finishing Method by Comparing whether Parallel winding and Cross Winding contribute a significant

effect for wire short.

Parallel

Cross

Sample X N Sample p 1 14 25 0.560000 2 24 25 0.960000 Difference = p (1) - p (2) Estimate for difference: -0.4

95% CI for difference: (0.609193, -0.190807)

Test for difference =0(vs not = 0):

Z =-3.75

P-Value = 0.000

-

Since P-Value < 0.05, Reject Ho

-

It’s mean that

Finishing Method

has an effect or SMPS reliability.

Finishing Method is

Vital Few factor

X

5 = Finishing Method (Winding Method)

Hypothesis Testing

Ho : P P 2 ( There are no different Proportion Between Parallel and Cross)

Ho :

P

≠

P

 ( There are different Proportion Between Parallel and Cross)

Cross Parallel

Sample Parallel Decision Sample Parallel Decision

1 P PASS 14 P PASS

(22)

16 - 22

Vital View

Material

Method

wire

Hole

Space

Cross

Core

Turn wiring

Home pin

Varnish

Dielectric Breakdown

Press

Short (No Power)

Vital View

Selecting Vital Factor

Need improved

Not need improved

(23)

Selecting Optimum Condition

• Dielectric Breakdown ( ↑ 2250 V and ↓ 2250V)

• Wire Hole (

↑ 5 and ↓5 / on 5 Meters

)

• Method Finishing Home Pin ( Cross and parallel)

Optimum condition :



_{Dielectric Breakdown :}

_↑

_{2250 V}



Pin Hole :

↓

5 hole / 5 m



Method Finishing : Parallel

P

C H +

H -DB +

DB -MTD H

DB

50

100 0

0

40

70 0

0

Cube Plot (data means) for PASS ( % )

Opt. Condition

DB PH MTD Pass %

DB - PH + P 0

DB - PH + C 0

DB + PH + P 50

DB + PH + C 40

DB + PH - C 70

DB + PH - P 100

DB - PH - P 0

DB - PH - C 0

In this Step, we try to find the optimum combination of all factors which have a

significant effect on SMPS Transformer Reliability.

(24)

Improvement

Improvement on Finishing Method at Samwha Process

Before :

Finishing wire of pin 12 is upper ( entered to home pin )

After :

Finishing wire of pin 10 is upper ( entered to home pin ) Finishing wire of pin 12 is lower then pin 10.

4 M Change Report

8

╚

╝

Cross Method Parallel Method

Change Wire Winding

(25)

Improvement

Improvement on Inspection Checking Method

Before

After

_After

Delivery

Sampling

Inspection (Conventional)

Storage Area Incoming

OK

NG IQC

• Appearance

• Size Supplier

Inspection

Check hole & D Breakdown

Storage Area Incoming

OK

NG IQC

• Appearance Size

• 5 m each roll wire ( test hole & D Breakdown ) Supplier

Sampling Delivery

IQC Samwha

• Involving new item inspection as an

new inspection check point :

•_{Check hole wire by Phenolphthalein}

( > 5 hole/5m, NG )

•_{Dielectric Breakdown test}

Content

_Content

Content

(26)

To keep good condition, we do :



Dielectric breakdown and hole wire control at wire vendor ( monthly )



Wire hole test before to production



Item CTQ Control



QC and Process Irregular Audit at Supplier



Total Inspection Part (100% Short Test)

D/B

I Chart of INDUCTANCE

Inductance

I Chart of RESISTANCE

CTQ

Maintain CTQ

(27)

Part production on March ~ May ‘04 are 245915 EA, SMPS Transformer defect: 1 ea

DPU = 1 : 184259 = 5.427E-6

▶

DPMO = 4 PPM , Sigma Level = 5.97

Condition part Oct ~ Dec’03

No Power by SMPS

Part No

BOIL BOIK OTHE RS

Condition part Mar ~ May ’04

No Power by SMPS

Part No

(28)

22 - 22