Usage of Six Sigma

• Six Sigma is not only a learning tool.

• Process improvement refers to a strategy of finding solutions to eliminate root causes of performance problems.

--Project --Manufacture

Actuality of Chinese Manufacture

• Defects in Manufacture Process• Assembly Line Defects• Sourcing Defects• Random Defects• Etc.

• Defects in Supply Chain• Transportation Inefficiency• Information Blocking

Defects and Six Sigma Levels

• Defect: anything that does not meet customer requirements.

e. g: a rude reception clerk is providing defective service.

• By measuring customer requirements.• By calculating defective opportunities:

DPMO

Critical ingredients

1. Continuous focus on customer2. Data and Fact-driven *3. Process focus

*get rid of unfounded assumptions.

Asking question: what data I need?

Why data is important?

• The company is growing more complex and the need for information on how things are operating is becoming more critical.

• The more complex of constraints the process have, the more difficult to identify problems by experiences.

Concise and exact way to evaluate process:

DATA

How to implement Six Sigma Project in Chinese Manufacture?

• The initiative of Six Sigma Project• Requirements of Quality by Vendor• The list of Six Sigma projects to fix

defects will be given by Vendor.• Supplier: Chinese manufacturer

• Methodology • Vendor will identify defect in

manufacturing supply chain using SIPOC model.

Identifying and Documenting the Process

• SIPOC

“Big Picture” perspective, additional detail can be added

supplierRaw

materialProcess Output Customer

Heading ThreadingHeat

treatmentDecarburization

Surface Discontinuities

Quality Inspection

N

Y

SIPOC

• Focus on the step (s) where the suspected causes of the symptoms in the Problem Statement

• Process: heading, threading, heat treatment, dec

arburization…

DefineDefine Measure Analyze Improve Control

• Customer requirements: quality of product keep a consistent level.

• e. g: bolts; packaging labels

• Chinese manufacturer should guarantee their products sustain that level

• e. g: take defect rate of 1,100(3 sigma) to 100(6 sigma) level.

Case A:

• Our goal: Find out weaknesses which hidden in the

process then improve it to meet the tolerance requirements.

• Two categories have to be identified: Load tests of bolts Tensile strength requirements

DDefineefine MeasureMeasure Analyze Improve Control

• Studying manufacturing process capability and quality characteristics

• Step 1: Collect data some variations?• Step 2: Make plot graph and diagram increase the power of data analysis

efforts. (EXCEL;MINITAB)

X-Bar chart for subgroup1,2

Sample

Sam

ple

Mean

121110987654321

35000

30000

25000

20000

15000

__X=24640

UCL=34101

LCL=15178

Sample

Sam

ple

StD

ev

121110987654321

10000

7500

5000

2500

0

_S=3559

UCL=11625

LCL=0

Xbar-S Chart of subgroup1, ..., subgroup2

Process capability chart

• Variation in process. It presents some defective samples below the lowest specification

2800024000200001600012000

LBProcess Data

Sample N 12

StDev(Within) 1528.21StDev(Overall) 3853.02

LB 24000

Target *USL *

Sample Mean 22214.2

Potential (Within) Capability

CCpk *

Overall Capability

Z.Bench *

Z.LB *Z.USL *

Ppk

Z.Bench

*Cpm *

*

Z.LB *Z.USL *

Cpk *

Observed Performance

PPM < LB 666666.67

PPM > USL *

PPM Total 666666.67

Exp. Within Performance

PPM < LB *

PPM > USL *

PPM Total *

Exp. Overall Performance

PPM < LB *

PPM > USL *

PPM Total *

WithinOverall

Process Capability of subgroup2

• Qualified bolts (all of samples)

290002800027000260002500024000

LBProcess Data

Sample N 12

StDev(Within) 624.678StDev(Overall) 850.571

LB 24000

Target *USL *

Sample Mean 27065.8

Potential (Within) Capability

CCpk *

Overall Capability

Z.Bench *

Z.LB *Z.USL *

Ppk

Z.Bench

*Cpm *

*

Z.LB *Z.USL *

Cpk *

Observed Performance

PPM < LB 0.00

PPM > USL *

PPM Total 0.00

Exp. Within Performance

PPM < LB *

PPM > USL *

PPM Total *

Exp. Overall Performance

PPM < LB *

PPM > USL *

PPM Total *

WithinOverall

Process Capability of subgroup1

Define Measure AnalyzeAnalyze Improve Control

• Recall the SIPOC diagram, identify areas where the process steps, responsibilities, or outcomes are unclear or produce no-value-added work.

• Pay attention on the first several procedures or work stations. (Bull-whip effect)

Variables in Process

• Z Value:

• Crossing Assembly Line and Transportation Process

• Information and Product Flow

4321 ,,, zzzz

Data/Material flow chart

manufacture

Process 1 Process 2 Process 3

Transportation Process 4customer

Information flow Information flowZ1 Z2 Z3

Product flow Product flow

Z4

• Final inspection data Find data to analysis and calculate.

• We could figure out the defects in every process, for example, in heat treatment .

• Have a hypothesis (Brainstorm), even their theories are wrong, have to be open to the possibility which supported by data.

• Hint: document all the case in process using table, graph, statistic software (MINITAB)…

Define Measure Analyze ImproveImprove Control

• Manufacturer transition diagram.

Customer vendor Chinese manufacture

Raw material supplier

Order

1Order

2order

3

Product

0Product

1Product

2

Supply chain (Markov Model)

Supply Chain Six Sigma Improvement

• Order/Information Flow and Product Flow

• Markovian queue--combine information and product flow

The customer, vendor, Chinese manufacturer and raw material supplier are in the chain where the external environment is a continuous time Markovian chain using data communication networks by order or product flow

Define Measure Analyze ImproveImprove Control

• Profit Margins • Continual Six Sigma improvement to str

eamline and cut the cost out of a supply chain.

Define Measure Analyze Improve ControlControl

• Go back to control chart (X-chart, R-chart ) and review it.

• Control limit recalculation.• Recording all the defective

opportunity.• Keep using control chart within

whole process.

Conclusion

• Six Sigma in manufacture process influences the decision making

• The first step:• Reducing DPMO based on the actual circum

stances by using statistic knowledge• Factors and Results

• The Second Step: • The Markovian model used in Supply Chain