chapter 10: principles of six sigma

8/12/2019 Chapter 10: Principles of Six Sigma

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MANAGING FOR QUALITY AND PERFORMANCE EXCELLENCE, 7e, 2008 Thomson Higher Education Publishing 1

Chapter 10

Principles of

Six Sigma


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MANAGING FOR QUALITY AND PERFORMANCE EXCELLENCE, 7e, 2008 Thomson Higher Education Publishing

Key Idea

Although we view quality improvement

tools and techniques from the

perspective of Six Sigma, it is important

to understand that they are simply a

collection of methods that have been

used successfully in all types of quality

management and improvementinitiatives, from generic TQM efforts, to

ISO 9000, and in Baldrige processes.


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Six-Sigma Metrics

Defectany mistake or error that ispassed on to a customer

Defects per unit (DPU)= number ofdefects discovered number of unitsproduced

Defects per million opportunities

(dpmo)= DPU 1,000,000 opportunities for error


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Six-Sigma Quality

Ensuring that process variation is half thedesign tolerance (Cp = 2.0) while allowing

the mean to shift as much as 1.5 standard

deviations, resulting in at most 3.4 dpmo.


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Key Idea

Although originally developed for

manufacturing in the context of tolerance-

based specifications, the Six Sigmaconcept has been operationalized to apply

to any process and has come to signify a

generic quality level of at most 3.4 defects

per million opportunities.


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k-Sigma Quality Levels


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Problem Solving

Problem: any deviation between what

should be and what is that is important

enough to need correcting Structured

Semistructured

Ill-structured

Problem Solving: the activity associatedwith changing the state of what is to what

should be


8/25MANAGING FOR QUALITY AND PERFORMANCE EXCELLENCE, 7e, 2008 Thomson Higher Education Publishing

Quality Problem Types

1. Conformance problems

2. Unstructured performance problems

3. Efficiency problems

4. Product design problems

5. Process design problems



Key Factors in Six Sigma

Project Selection Financial return, as measured by costs

associated with quality and process

performance, and impacts on revenues andmarket share

Impacts on customers and organizational

effectiveness

Probability of success

Impact on employees

Fit to strategy and competitive advantage



Problem Solving Process

1. Redefining and analyzing the

problem

2. Generating ideas

3. Evaluating and selecting ideas

4. Implementing ideas



Key Idea

A structured problem-solving process

provides all employees with a common

language and a set of tools tocommunicate with each other,

particularly as members of cross-

functional teams.



DMAIC Methodology

1. Define

2. Measure3. Analyze

4. Improve

5. Control



Common Six Sigma Tools



Define

Describe the problem in operational

terms

Drill down to a specific problemstatement (project scoping)

Identify customers and CTQs,

performance metrics, and cost/revenueimplications


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Measure

Key data collection questions

What questions are we trying to answer?

What type of data will we need to answerthe question?

Where can we find the data?

Who can provide the data?How can we collect the data with minimum

effort and with minimum chance of error?


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Analyze

Focus on why defects, errors, or

excessive variation occur

Seek the root cause

5-Why technique

Experimentation and verification


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Improve

Idea generation

Brainstorming

Evaluation and selection

Implementation planning


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Control

Maintain improvements

Standard operating procedures

Training

Checklist or reviews

Statistical process control charts


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Tools for Six-Sigma and

Quality Improvement Elementary statistics

Advanced statistics

Product design and reliability

Measurement

Process control

Process improvement Implementation and teamwork


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Design for Six Sigma

Focus on optimizing product and processperformance

FeaturesA high-level architectural view of the design

Use of CTQs with well-defined technicalrequirements

Application of statistical modeling and simulationapproaches

Predicting defects, avoiding defects, andperformance prediction using analysis methods

Examining the full range of product performanceusing variation analysis of subsystems andcomponents


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Key Idea

All Six Sigma projects have three key

characteristics: a problem to be solved,

a process in which the problem exists,and one or more measures that quantify

the gap to be closed and can be used to

monitor progress.


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Key Six Sigma Metrics in

Services

Accuracy

Cycle time

Cost

Customer satisfaction


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Lean Production and Six

Sigma

The 5Ss: seiri (sort), seiton (set in order),seiso (shine), seiketsu (standardize), andshitsuke (sustain).

Visual controls Efficient layout and standardized work

Pull production

Single minute exchange of dies (SMED)

Total productive maintenance

Source inspection

Continuous improvement


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Traditional Economic Model of

Quality of Conformance

Total cost

Cost due to

nonconformanceCost of

quality

assurance

optimal level of quality100%


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MANAGING FOR QUALITY AND PERFORMANCE EXCELLENCE 7 2008 Th Hi h Ed ti P bli hi

Modern Economic Model of

Quality of Conformance

Total cost

Cost due to

nonconformanceCost of

qualityassurance

100%

chapter 10: principles of six sigma

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