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Table of Content

1. Introduction 2. Process Control flow chart 3. Measurement System Capability 4. Process Performance Metrics 5. Product/Process Improvement flow chart

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Nature of the Manufacturing Process

* Due to uncontrollable variations, the units produced are different from the design target and from each other.

* The unit-to-unit variations usually follow a normal distribution (Figure 1).

The standard deviation of the distribution, Sigma ( ), is a

measure of the amount of the variation.

Figure 1Normal distribution of process variation is represented by a bell-shaped curve.

σ

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Traditional Process Capability

* Traditionally, a process was judged to be satisfactory with a 3 sigma capability with centreline at target.

* For a 3 sigma process, 99.73 % units produced conform to specification, 0.27% (2,700 ppm) out of specification (Figure 2).

* With 1.5 Process shift from target, only 93.32 % conform to spec whereas 6.68% (66,800 ppm) out of specification (Figure 3).

Traditional 3 Sigma capability Three sigma capability process with a typical shiftFigure 2 Figure 3

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Six Sigma Capability

* With a six sigma process capability with centre at target, only 0.002 ppm defective units produced (Figure 4).

* In reality, very few processes are perfectly centered. Process shift of # 1.5 sigma is typical. With six sigma process capability and 1.5 process shift, only 3.4 ppm defective units produced (figure 5).

# Refer to Benda. (1975) tatistical Tolerancing as it Relate Quality Control and the Designer?Automotive Division Newsletter Evans, David H. (1975) tatistical tolerancing : The State of the Art, Part II : Methods for Estimating Moment

A centered 6 sigma process. A 6 sigma process with typical 1.5 sigma shiftFigure 4 Figure 5

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Six Sigma & Beyond ....

* When six sigma goal is reached, room for improvement still remains for achievement of Total Customer Satisfaction.

* Motorola continues striving for 10-fold reduction in defects every two years with quality goal set beyond the six sigma.

* The unit for quality measurement is defined at kppb level.

* To archive this level of performance, we have to strive for a centered process and minimise process variation. With a centered & six sigma process, only 2 ppb defects appear.

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JAD000502

Summary of Process Control Chart

Evaluate Metrology

MSA OK?

Test process stability

Process Stable?

Collect Enough data

Normal Distribution?

Calculate Cp/Cpk

Cp/Cpk OK?

Review Control Limits

Continuous Improvement

Reduce Variation

Stabilize process

Transform data

Optimize Process

Y

N

YN

N

Y

Y

NN

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Measurement System Capability

* The capability of the measurement system must be ensured before the system is used for process control or process capability study.

* A measurement system consists of a gage, the people who use it, the techniques, procedures, etc..

* A measuring system must be assessed using appropriate statistical studies for Accuracy, Stability, Linearity, Repeatability & Reproducibility. The studies should be

repeated periodically. Local organizations should establish time guidelines for repeating these studies.

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Why Gage Capability is important

* The Process Variation, SigmaTotal, actually combined of two components : the process variation itself and the gage variation :

* Suppose we have a centered process (Cp = Cpk) which has an allowable tolerance of +/- 10. The gage variation is 2.5. Suppose the Process Variation is zero (an impossibility).

For this process, Cpk will never exceed 1.33 because of gage variation.

222GageprocessTotal SigmaSigmaSigma +=

22 0 GageTotal SigmaSigma +=

33.15.26

206 2 =

×=

×==

Totalppk Sigma

SpecCC

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Gage Repeatability & Reproducibility (R&R) Studies

* A typical gage R&R study is done using three different operators measuring the same set of 10 parts.

* The study will result in two components : variation due to instrument (repeatability) and variation due to the operators (reproducibility).

* The two components are combined into one single R&R number.

* The R&R number then is compared with either the process variation (5.15 Sigma) or allowable tolerance. The results is a gage R&R Percentage (%R&R).

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* Traditionally, the gage error was compared with the part tolerance to estimate the %R&R resulting in P/T ratio. This practice is no longer recommended as our interest is to find out a gage is capable characteristic which has its own uniquely variability.

Precision-to-Tolerance Ratio (P/T Ratio)

* With Motorola Six Sigma program, an otherwise capable gage as determined by a small P/T ratio may not be capable for a process

with small process variability.

* For the purpose of calculating the gage %R&R, the process variability is defined as 5.15 sigmas. (Number chosen by #AIAG while developing GR&R study. 5.15 sigma represents 99% area under normal curve)

%R&R R&R x 100Process Variability

= = R&R x 1005.15 sigma

# : Automotive Industrial Action Group

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GAGE CAPABILITY & REPRODUCIBILITY STUDY

GAGE TYPE : IQ1500 TV USED : UCL represents the limit of

PART MEASURED : 17CSH00768A COMBINED R&R AND PV individual R's. Circle those

CHARACTERISTIC : DIMENSION (DOWNSET DEPTH) PROCESS 5.15 SIGMA ranges that are beyond this

SPEC : 0.16 - 0.26 UNIT : MM X PART'S TOLERANCE limit. Identify the cause and1 2 3 4 5 6 7 8 9 10 AVG AVERAGE /R = (/RA+/RB+/RC) correct. Repeat those

1 0.183 0.190 0.188 0.202 0.195 0.194 0.201 0.194 0.201 0.184 0.193 /X(diff) = /X(max) no. of operators readings using the sameOperator 2 0.180 0.195 0.196 0.201 0.197 0.197 0.205 0.192 0.205 0.186 0.195 /XA = - /X(min) = 0.003 operator and units as originally

A 3 0.185 0.190 0.187 0.203 0.199 0.198 0.204 0.194 0.205 0.184 0.195 0.195 = 0.000 UCLR = /R * D4 used or discard those readings R 0.005 0.005 0.009 0.002 0.004 0.004 0.004 0.002 0.004 0.002 /RA = 0.004 = 0.008 and reaverage and recompute

1 0.180 0.195 0.185 0.201 0.194 0.194 0.204 0.194 0.204 0.184 0.194 # TRIALS D4 K1 OPERATORS K2 ranges and UCL from theOperator 2 0.185 0.193 0.185 0.204 0.196 0.196 0.206 0.196 0.206 0.186 0.195 /XB = 2 3.27 4.56 2 3.65 remaining readings.

B 3 0.185 0.195 0.184 0.205 0.195 0.194 0.204 0.195 0.205 0.185 0.195 0.195 3 2.56 3.05 3 2.7 R 0.005 0.002 0.001 0.004 0.002 0.002 0.002 0.002 0.002 0.002 /RB = 0.002 PARTS 2 3 4 5 6 7 8 9 10

1 0.183 0.195 0.187 0.210 0.196 0.195 0.201 0.192 0.205 0.185 0.195Operator 2 0.180 0.190 0.185 0.205 0.192 0.198 0.204 0.193 0.204 0.185 0.194 /XC = K3 3.65 2.70 2.30 2.08 1.93 1.82 1.74 1.67 1.62

C 3 0.184 0.192 0.183 0.204 0.195 0.194 0.204 0.192 0.204 0.184 0.194 0.194 R 0.004 0.005 0.004 0.006 0.004 0.004 0.003 0.001 0.001 0.001 /RC = 0.003n = number of parts =10 r = number of trials = 3

tot. readngs 1.645 1.735 1.680 1.835 1.759 1.760 1.833 1.742 1.839 1.663 AV DEFAULTS TO ZERO IF A NEGATIVE IS no. of operators = 3Avg /Xp 0.183 0.193 0.187 0.204 0.195 0.196 0.204 0.194 0.204 0.185 RangeRp = 0.022CALCULATED UNDER THE SQUARE ROOT SIGN

REPEATABILITY (EV) REPRODUCIBILITY (AV) COMBINED R & R PART VARIATION (PV) TOTAL VARIATION (TV)

ANALYSIS EV = /R * K1 AV = SQRT((X(diff)*K2)^2- R&R = SQRT(EV^2 PV = Rp * K3 TV = SQRT(R&R^2 + PV^2) = (EV^2/(n*r))) +AV^2) OR

TV = 5.15 * PROCESS

EV = 0.010 AV = 0.000 R&R = 0.010 PV = 0.035 STD. DEVIATION = OR

% PROCESS %EV = 100(EV /TV) %AV = 100(AV / TV) %R&R = 100(R&R/TV) %PV = 100*(PV/TV) TV = PART's TOLERANCE = 0.100VARIATION

%EV = 9.963% %AV = 0.000% %R&R = 0.100 %PV = 34.92% TV = 0.100

P/T Ratio = 100%*(R&R)/Tolerance =N/A

Figure 6. Typical example of GR&R report

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Under 10% Measuring system is acceptable

10% - 30 % May be acceptable based upon the important of theapplicable, cost of gage, cost of repair or otherconsideration.

Over 30% Error is not acceptable; make every effort to identifythe measurement problem and get it impoved. In anycase, run another GR&R study after improving of theproblem to see if the %R&R will go down to theacceptable level before releasing to use.

Gage R&R and P/T ratio Acceptance Guidelines

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Gage Calibration Interval Determination

* Gage calibration interval must be determined by appropriate technique.

* If arbitrarily chosen, the intervals might be too frequent (waste resources) or too far apart (risk of using inaccurate gage).

* For these reasons, gage calibration intervals should be carefully determined. Either an algorithmic method or a statistical method should be employed to establish and adjust the gage calibration intervals, to minimize the risk and optimize resources.

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PROCESS PERFORMANCE METRICS

There are three valuable metrics that must be used to measure the performance of all significant processes :

(1) Potential Process Capability (Cp) (2) Process Capability Index (Cpk) (3) Instability Index (St)

(1) and (2) are used to assess process capability and (3) is used to determine the stability of a process.

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Potential Process Capability Index (Cp)

Cp index is defined as the ratio of specification width over the process spread.

Sigma6LSL-USL

Spread Process WidthSpec.

×==pC

Figure 13. Potential Capability Index Cp

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Process Capability Index (Cpk)

Cpk is the index to measure this real capability when the off-target penalty is taken into consideration.

The penalty, or correction factor, k is defined as :

and the Process Capability index is defined as :

Cpk = Cp ( 1 - k )

When the process is perfectly on target :

k = 0 and Cpk = CpFigure 14. Capability Index Cpk

k = −−−−−−−−−−−−−−−−−−Target - Process Mean

1/2 (Spec. Width)

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In the following cases :

--- When the target is not specified --- When the target is in the middle of two specification limits --- When there is a one-sided spec. limit.

Cpk may be more conveniently calculated as :

Cpk =Mean - closer Spec. Limit

---------------------------------3 sigma

Note : This formula cannot be used when the specified target is not in the center of the two specification limits.

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Use of Cp and CpkCp and Cpk are used to determine the capability of a process.Cp, when shown together with Cpk, gives a quick estimate of how far the actual process is from its target, thus how much work is needed to bring the process to its potential.

Cpk and process stability :Cpk is a meaningful measure of process capability only when a process is in statistical control.Cpk and normality of data :Because of the definition of Cp and Cpk are for normal distribution, the data to be used for Cp and Cpk calculation should be tested for normality.

Cpk for a non-normal distribution :Generally, there are three techniques which can be conveniently used for non-normal distributions :1) Transform the data into a normal distribution. 2) The non-normal data may be fitted using an empirical model. 3) Using the conventional method.

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Instability Index (St)

Instability index, or St, provides a means of estimating whether assignable causes are present in the process.

The instability index St is calculated as :

St =Number of out-of-control data points

Total number of data points---------------------------------------------- x 100 %

If all data points are in control, St will be zero.If all of the points are out of control, St will be 100 %

The instability index is correctly interpreted as the percent instability present in the process.

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Cp = 2.0

Cp does not effect the process capability, need to check the Cp and Cpk simultaneous!

Cpk = 1.0 Cpk = 2.0 Cpk = 1.0

LSL TARGET USL

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Cp = 1.5

Cp = 3.0

Cp = 2.0

Cp = 6.0

LSL USLTARGET

Cpk = 1.5

Cpk does not effect the process capability too, need to Check the Cp and Cpk simultaneous!

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Cp

0.5

1.0

2.0

10

Process capability - Cp and Cpk

LSL=40 USL = 100Tbar = 70

ST = 20

ST = 10

ST = 5

ST = 1

Approx Fallout 1%

Approx Fallout 0.00000018%

Approx Fallout 13.4%

Approx Fallout 0.00000000%

Cpk

0.5

1.0

2.0

10

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1. Reason 3. Understand & confirm losses

4. Prioritize problems

6. Evaluation & Analysis

5. Implementation Plan

7. Corrective Actions 8. Confirm Effects

9.Institutionalization10. Future Plans

? • Clearly explain the reason why the team was formed • State the critical business issue confronting them and the opportunities

Overall Loss1st level

Losses Structure

3rd levelPareto of loss

2nd level

Loss Trend A

Loss Trend B

A. Unit stuck at input track B. Unit drop at sort shuttle C. Contactor finger broken

No. Activities1. 2. 3. 4.

AM1- Clean & restore AM2- C/measures AM3- Estb. Stds. Problem analysis

Timeline

Why 1 Why 2

Phenomenon

Why 3

• Understand problem and have full grasp of facts & phenomenon • Always check for logical correctness of each Why • Continue Why until it leads to solution • Verify all factors by thinking in reverse

Training Plans

Standard RevisionOne

Point Lesson

PM Chk.list

No. Action Items Resp. Date Status

1. 2. 3.

Action Item A Action Item B Action Item C

X Y Z

Action Followup

1/1 2/2 3/3

Time

L o s s e s

Action Item A

Action Item B

Action Item C

Improve Machine # 1 and carryout horizontal expansion to all machine M/c # 1 ...................... ww10 M/c # 2 ...................... ww15 M/c # 3 ...................... ww18 M/c # 4....................... ww21

Done Done

Troubleshooting Guide

• Establish baseline and set targets

BM

SMART Goals

2. Target

Product/Process Improvement Flow Chart

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Project Selection1aStep

Define clearly the Reason for this team to be formed.

State the critical business issue confronting the team and the opportunities Selection should be based on any of the following issues below:

1. Bottlenecks /Capacity 4. Delivery 2. Quality 5. Productivity 3. Yield Issues 6. Cost

Tools : Pareto Analysis Benchmarking Quality/RMA reports Yield reports 8-D report Failure Analysis reports

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REASON1bStep

CAPACITY CONSTRAINT

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

July Aug Sept Oct Nov DecMONTH

TEST

ER

CapacityAvailable

J971 TOP PRODUCT

360EM43%

860ZP26%

850ZT10%

5244PV9%

060RC6%

823ZT/ZC5%

5206FT1%

DELINQUENCY IN DOLLAR

6836027%

6830224%

860/82120%

EN30211%

LC3026%

850/8015%

686063%

FDDI2%

Limited Capacity

UTS handler Our

MainTarget

Top Product

Highest Delinquency

SAMPLE

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REASON1bStep

Limited Capacity

Top Product

Highest Delinquency

UTS handler was taken as our main focus of attention due to :

SAMPLE

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Name of Team : ................................... Operation : ...................................

Equipment or : ................................… Process Team Leader : ...............................…. Secretary : ................................... Members:……………………………….. ........................................….. .............................................. .............................................. .........................................…. ..................................………. Meeting Schedule :…………………. ............................…………... Meeting Place: ............................... .............................................. Meeting Time : ............................... …...................................…… Duration : ............................... ………………………………...

Team Formation1cStep

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Members NameWorkweek

10

20

30

40

50

60

70

80

90

100

PERC

ENTA

GE

WORKWEEK

5 10 15 20 25 30

Team Name: Dept :

Legend : P (Present) X (Absent) A (Annual Leave) MC (Medical leave) T (Training) H (Holiday)

Team Attendance Chart1dStep

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Target2aStep

S pecific : ........................

M easurable : ........................

A chievable : ........................

R ewarding : ........................

T imebased : ........................

Select Model Machine and start data collection to identify the 8 Major Losses.

Review data collection over two weeks period.

Establish Baseline of selected equipment

Set S.M.A.R.T. goal

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2bStep

Target

To Improve the Utilization of the ADV Tester System (T33xx) for the AZ/AB series product family

from 52% to 60 % by Sep’99 & from 60% to 65% by Dec’99

SAMPLE

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3aStep

Understand and Confirm Losses

Overall Loss (1st level )

Losses Structure

(3rd level)Pareto of loss

(2nd level)

Loss Trend A

Loss Trend B

Team identify the overall loss structure and pareto the loss to determine the top 2 or 3 issues that need to be worked on.

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Breakdown of V/M Yield loss

0102030405060708090

100

Coplana

rity

Meas Error

Bent Le

ad Bow Mark Pitch

Yield(

%)

COPLANARITY SHIFT ANALYSIS ON BINNER

0

0.05

0.1

0.15

0.2

0.25

Frombinner

to metalrail

Frombinner

toplastic

FromFlipper

toBinner

COPL

A SH

IFT

(mils

)

COPLANARITY SHIFT ANALYSIS ON S400-13

00.020.040.060.08

0.10.120.140.160.18

0.2

BINNER LOADER STORAGE TEST TRACK

COPL

A S

HIF

T (m

ils)

Coplanarity Mapping (% of leads with copla >3.0 mils)

1061

609

4443 27

26

5% 5%

30%

15%

5% 5%

15%

20% 1

side 2

side 3

side 4

3aStep

Understand and Confirm LossesSAMPLE

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4aStep

Prioritize Problems

Input Track jam

Core pickup

Setup Time

1

2

3

SAMPLE

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5aStep

Implementation Plan

Setup a milestone chart to determine the period required to do Autonomous Maintenance Step 1 to 3 followed by the problem analysis as described in the prioritized list in step 4

TimelineActivities 20 21 22 23 24 25 26 27 28 29 30

AM Step 1 - Clean, Tag & Restore

AM Step 2 - Countermeasures

AM Step 3 - AM Standards

Problem AnalysisInput Track

Core Pickup

Setup Time Reduction

PlanActual

SAMPLE

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Analysis Tools

Why-Why P-M Fault Tree

Evaluation And Analysis

6aStep

Understand problem and have full grasp of facts & phenomenon

Apply any of the following techniques such as Fault Tree, Why-

Why, P-M, FMEA...

Always check for logical correctness of each Why

Continue Why until it leads to solution

Verify all factors by checking the “why” in reverse

IMPORTANT IS Genba & Genbutsu

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Pusher cylinder limitsensor not set properly

Pusher cylinderjammed

Pusher did not pushat right position

Clamp motor jammed

Clamp bearing jammed

Bent frame

Magazine to trackout of alignment

Pusher bent

Pusher thicknessnot appropriate

Magazine not sittingproperly on elevator

Elevator not movingsmoothly

T/F operator handlingFrom previous processes

Straighten pusher

Modify pusherplate to 5mm thick

Perform strip checkthoroughly

Why-Why Analysis

Infeed Error ( Leadframe did not reach S13 )

Infeed Pusher Leadframe

Pusher not hitting atthe right position

Pusher bent and notat right angle <90‘

Pusher modified thickerwith concave tip. Misfeed solved

Phenomenon Countermeasure

NG

NG

NG

NG

OK

OK

OK

OK

OK

OK

OK

NG

Why 1 Why2

SAMPLEEvaluation And Analysis

6Step

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Step 0: Select Improvement Topic

P-M Analysis Flow

Achieving Zero Defect by Eliminating Chronic Losses using P-M Analysis

Chronic loss1 %A B C D

0

20

40

60

80

100

A B C D

A B C D0

40

80

A B C D

P-M Analysis

Item “B” Improvement

Reduced to ZERO

Prioritize problems by defect type.

Item “A” ImprovementP-M Analysis

Chronic loss1 %

“A” Improvement

“B” Improvement “C”

Improvement

Evaluation And Analysis

6Step

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Step 4: Plan Improvement

CUSTOMER: OPERATION: KLM ATTENDEES:

SUBJ: DATE:

ACTION RESPONSIBLE DATE STATUS

ACTION COORDINATOR:

INFO COPY:

STATUS UPDATE BY: FOLLOW-UP MEETING:

ACTION FOLLOW -UPCorrective Actions7

Step

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Step 5: Implement ImprovementConfirm Effects 8Step

Verify that the actions taken as a result of the countermeasures from the analysis corresponds to the improvement made as shown in the graph.

Input Quad Head Motor Jam Statistic

-15-10-505

101520253035404550

37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52

01'99

02'99

03'99

04'99

05'99

06'99

07'99

08'99

09'99

10'99

11'99

12'99

13'99

14'99

15'99

16'99

17'99

18'99

WorkWeek

Jam

s

ReDesign Input nest

Reduced Input ATU Elevator speed Redesign Input

Elevator Catch with additional 1mm

* Performed Full X-Y alignment* Applied Screw Loctite on X-Y Tensioning screw * Lowering Z-pick up head

123 Goal = '0' jam

One major loss

eliminated !

SAMPLE

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Institutionalization9Step

One Point

Lessons

Trouble- shooting guide

No. Activities1. 2. 3. 4.

Timeline

Training plans

PM ChecklistPM Checklist

Use OPL’s to train and educate all personnel

Modification or Changes in design should be incorporated into the Preventive Maintenance checklist

Create step by step trouble- shooting guide for tech’s and operators to reduce MTTR(mean time to repair)

Provide training to all to enhance knowledge and skills

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Future Plans10Step

Improve Machine # 1 and carryout horizontal expansion to all machine

Fan out item Completion date Machine No.UTS1 UTS2 UTS3 UTS4 UTS5 UTS6 UTS7 UTS8 UTS9 UTS10UTS11

1. N2 Purge ring WW 10

2. LN2 cover WW21

3. Gauge Indicator WW18

4. Temper proof sticker WW18

5. Tray hole cover WW20

6. Greasing on Pusher Assy. WW26

7. Screw loctite for critical alignment WW27

8. Magnetic clip on core cover WW27

9. Handle for Input cover WW27

10. Input elevator catch WW12

11. Scrap container WW14

12. Ventilation fan ribbon WW16

SAMPLE

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TPM Manager Model - Fan out Activities Date Ase#15Ase#7 Ase#13Ase#4 Ase#8 Ase#17Ase#9 Ase#3 Ase#14Ase#6

1Venturi Vacuum System WW342Repainting of machine coversWW303Magnetic latch on all covers WW304Add filter under card cage WW155Frost free LN2 piping WW356Complete rewiring of machine wiring WW287Floor hole cover WW308Tube height guide scale coverWW259Binner station hole cover WW25# Andon light wiring rewiring WW18# Arrow marks on gauges and flow meters WW24# Fan status indicator ( Ribbon )WW24# Spring washer on chamber trackWW24# Input entrance track cover WW30# Rubber mat on manipulator WW26# Fixing fuguai's WW30

Future Plans10Step SAMPLE

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Your team has breakthrough and achieved your improvement topic. Celebrate your team success.

Congratulations !

Select Next Improvement

Review latest losses structure.

Select next improvement topic.

Repeat improvement cycle.

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Welcome inquiry1,Please visit : www.smthelp.com

2, Find us more: https://www.facebook.com/autoinsertion

3, Know more our team: https://cn.linkedin.com/in/smtsupplier

4, Welcome to our factory in Shenzhen China

5, Look at machine running video: https://www.youtube.com/jasonwuSMT

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