SIX-SIGMA QUALITY

Chapter 9

1. Understand total quality management.

2. Describe how quality is measured and be aware of the different dimensions of quality.

3. Explain the define, measure, analyze, improve, and control (DMAIC) quality improvement process.

OBJECTIVES 9A-2

Key Six Sigma Concepts

Critical to quality: attributes most important to the customer

Defect: failing to deliver what customer wants Process capability: what your process can

deliver Variation: what customer sees and feels Stable operations: ensuring consistent,

predictable processes to improve what the customer sees and feels

Design for six-sigma: designing to meet customer needs and process capability

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Total Quality Management (TQM)

Total quality management is defined as managing the entire organization so that it excels on all dimensions of products and services that are important to the customer

9-4

Malcolm Baldridge National Quality Award Established in 1987 by Department of

Commerce Goal is to help companies review and

structure their quality programs Has requirement that suppliers

demonstrate they are measuring and documenting their quality practices

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Quality Specifications

Design quality: Inherent value of the product in the marketplace

Dimensions include: Performance, Features, Reliability/Durability, Serviceability, Aesthetics, and Perceived Quality.

Conformance quality: Degree to which the product or service design specifications are met

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The Dimensions of Design Quality Performance: primary product or

service characteristics Features: added touches, bells and

whistles, secondary characteristics Reliability/durability: consistency of

performance over time Serviceability: ease of repair Aesthetics: sensory characteristics Perceived quality: past performance

and reputation

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Costs of Quality

External Failure Costs

Appraisal Costs

Prevention Costs

Internal FailureCosts

Costs ofQuality

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Six-Sigma Quality

Six-sigma is a philosophy and methods used to eliminate defects

Seeks to reduce variation in the processes

One metric is defects per million opportunities (DPMO)

000,000,1units ofNumber unit per error for iesopportunit ofNumber

defects ofNumber DPMO

LO 2LO 2

Six-Sigma Methodology

Uses many of the same statistical tools as other quality movements Used in a systematic project-oriented

fashion through define, measure, analyze, improve, and control (DMAIC) cycle More detailed version of Deming PDCA cycle

Continuous improvement: seeks continual improvement in all aspects of operations Also uses scientific method

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Six Sigma Quality: DMAIC Cycle

Define, Measure, Analyze, Improve, and Control (DMAIC)

Developed by General Electric as a means of focusing effort on quality using a methodological approach

Overall focus of the methodology is to understand and achieve what the customer wants

A 6-sigma program seeks to reduce the variation in the processes that lead to these defects

DMAIC consists of five steps….

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Analytical Tools for Six Sigma and Continuous Improvement: Flow Chart

No, Continue…

Material Received

from Supplier

Inspect Material for

DefectsDefects found?

Return to Supplier for Credit

Yes

Can be used to find quality problems

Can be used to find quality problems

9-12

Analytical Tools for Six Sigma and Continuous Improvement: Run Chart

Can be used to identify when equipment or processes are not behaving according to specifications

Can be used to identify when equipment or processes are not behaving according to specifications

0.440.460.480.5

0.520.540.560.58

1 2 3 4 5 6 7 8 9 10 11 12Time (Hours)

Dia

me

ter

9-13

Analytical Tools for Six Sigma and Continuous Improvement: Pareto Analysis

Can be used to find when 80% of the problems may be attributed to 20% of thecauses

Can be used to find when 80% of the problems may be attributed to 20% of thecauses

Assy.Instruct.

Fre

quen

cy

Design Purch. Training

80%

9-14

Analytical Tools for Six Sigma and Continuous Improvement: Check sheet

Billing Errors

Wrong Account

Wrong Amount

A/R Errors

Wrong Account

Wrong Amount

Monday

Can be used to keep track of defects or used to make sure people collect data in a correct manner

Can be used to keep track of defects or used to make sure people collect data in a correct manner

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Analytical Tools for Six Sigma and Continuous Improvement: Histogram

Nu

mb

er

of

Lo

ts

Data RangesDefects

in lot

0 1 2 3 4

Can be used to identify the frequency of quality defect occurrence and display quality performance

Can be used to identify the frequency of quality defect occurrence and display quality performance

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Analytical Tools for Six Sigma and Continuous Improvement: Cause & Effect Diagram

Effect

ManMachine

MaterialMethod

Environment

Possible causes:Possible causes: The results or effect

The results or effect

Can be used to systematically track backwards to find a possible cause of a quality problem (or effect)

Can be used to systematically track backwards to find a possible cause of a quality problem (or effect)

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Analytical Tools for Six Sigma and Continuous Improvement: Control Charts

Can be used to monitor ongoing production process quality and quality conformance to stated standards of quality

Can be used to monitor ongoing production process quality and quality conformance to stated standards of quality

970

980

990

1000

1010

1020

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

LCL

UCL

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Poke

-Yoke

Cutting leather where ‘A’ placed with no defects or marks; ‘B’ with some; and ‘C’ with more than B allowed.

Vis

ual

Man

ag

em

en

t

Other Six Sigma Tools

Failure Mode and Effect Analysis (DMEA) is a structured approach to identify, estimate, prioritize, and evaluate risk of possible failures at each stage in the process

Design of Experiments (DOE) a statistical test to determine cause-and-effect relationships between process variables and output

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Six Sigma Roles and Responsibilities

1. Executive leaders must champion the process of improvement

2. Corporation-wide training in Six Sigma concepts and tools

3. Setting stretch objectives for improvement

4. Continuous reinforcement and rewards

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External Benchmarking Steps

1. Identify those processes needing improvement

2. Identify a firm that is the world leader in performing the process

3. Contact the managers of that company and make a personal visit to interview managers and workers

4. Analyze data

9-23

ANY QUESTIONS?