Chapter 11 – Part IChapter 11 – Part ITotal Quality ManagementTotal Quality Management

COB 300COB 300BusingBusing

Problems Hidden by Inventory

Simplifying the Process

• Plant layout• Group technology• U-shaped layout• Reducing setup time• Total preventive

maintenance

Simplified Process

Strategy and JIT

• Quality and reliability• Flexibility

– product– volume

• Dependability• Asset utilization• People utilization• Cost minimization

Internally OrientedInternally OrientedDefinitions of QualityDefinitions of Quality

Quality is the degree to which a specific product conforms to a design or specification

Differences in quality amount to differences in the quantity of some desired ingredient or attribute

Externally OrientedDefinitions of Quality

• Quality is fitness for use• Quality consists of the capacity to satisfy wants

A Definition of Quality Used by Many Companies

Quality is consistently meeting or exceeding the customer’s needs and expectations.

Dimensions of Service Quality

• Reliability• Responsiveness• Assurance• Empathy• Tangibles

Dimensions of Quality for Goods

• Performance• Features• Reliability• Conformance

• Durability• Serviceability• Aesthetics• Perceived Quality

Costs of Quality

• Prevention– Planning– Procedures– Training

• Appraisal– Testing– Inspection– Audits

• Failure– Internal

• Scrap and rework• Retests• Down time

– External• Returns• Warranty work• Goodwill lost• Lost sales

The Background of TQM

• W. Edwards Deming– System causes most

defects• Joseph M. Juran

– Quality planning, quality control, quality improvement

• Philip Crosby– Quality is free, zero

defects• Genichi Taguchi

– Taguchi methods, robust design

Components of TQM

• Focus on the customer• Everyone responsible for

quality• Team problem solving• Employee training• Fact-based management• Philosophy of continuous

improvement

Components ofContinuous Improvement

• Standardize and document procedures• Assign teams to identify areas for

improvement• Use methods analysis and problem-solving

tools• Use the Plan-Do-Check-Act cycle• Document improved procedures

The Plan-Do-Check-Act Cycle

Baldridge Award

• Baldridge Award Criteria for 00

ISO 9000 Standards9000-1: Guidelines9001: Design through installation and

testing9002: Production through installation

and testing9003: Distributors9004-1: Model of quality management

system

Comparing Baldrige,ISO 9000 and TQM

• Baldrige– U.S. Quality Award– Focus on outcomes

• ISO 9000– International standards– Focus on documentation of processes

• TQM– Organizational quality philosophy– Foundation of Baldrige criteria

Chapter 11 – Part IIChapter 11 – Part IIQuality Control Quality Control

COB 300 C - The Operations DimensionCOB 300 C - The Operations DimensionBusingBusing

Causes of Variation

• Random Causes– difficult or expensive

to control– e.g., outside humidity,

line voltage• Assignable Causes

– easier to correct– e.g., employee error,

new materials

Comparing Process Variation to Tolerance Limits

High Process Capability After Technological Process Change

Control Charts• Variables - concentrates on mean for some

measurable characteristic.– diameter– length

• Attribute - data is based on counts or the number of times we observe a particular event.– proportion defective/non-defective– go/no go– proportion pass/fail

Control Limits - Variables Charts

X-Bar Chart

R Chart

UCLx x 3

LCLx x 3

X A R2

UCL D RR 4LCL D RR 3

X A R2

Variables Control Chart Examples: Compute the 3 control charts for X and R from 15 samples ofsize n=3. Plot the control limits and the Xand R values and comment about the underlying process.

Sample OBSERVED DIMENSIONS (cm)1 4.843 4.863 4.8592 4.925 4.882 4.8913 4.866 4.914 4.8734 4.852 4.883 4.885 4.92 4.884 4.8216 4.915 4.902 4.8987 4.887 4.892 4.8588 4.868 4.888 4.8429 4.904 4.863 4.86610 4.921 4.92 4.89411 4.914 4.884 4.89912 4.892 4.896 4.88713 4.866 4.829 4.8814 4.85 4.875 4.87215 4.867 4.9 4.885

Variables Control Chart Examples: Compute the 3 control charts for X and R from 15 samples of size n=3. Plot the control limits and theXand R values and comment about the underlying process.

Sample OBSERVED DIMENSIONS (cm) mean range1 4.843 4.863 4.859 4.855 0.0202 4.925 4.882 4.891 4.899 0.0433 4.866 4.914 4.873 4.884 0.0484 4.852 4.883 4.88 4.872 0.0315 4.92 4.884 4.821 4.875 0.0996 4.915 4.902 4.898 4.905 0.0177 4.887 4.892 4.858 4.879 0.0348 4.868 4.888 4.842 4.866 0.0469 4.904 4.863 4.866 4.878 0.041

10 4.921 4.92 4.894 4.912 0.02711 4.914 4.884 4.899 4.899 0.03012 4.892 4.896 4.887 4.892 0.00913 4.866 4.829 4.88 4.858 0.05114 4.85 4.875 4.872 4.866 0.02515 4.867 4.9 4.885 4.884 0.033

4.882 0.037

Factors for Control Limits(Slide 1 of 2)

23456789

10

1.8801.0230.7290.5770.4830.4190.3730.3370.308

000000.0760.1360.1840.223

3.2682.5742.2822.1142.0041.9241.8641.8161.777

n A2 D3 D4

Sample of Size

844.4)037(.023.1882.4

920.4)037(.023.1882.4

x

x

LCL

UCL

x-bar Chart Example (cont’d)

Six Sigma Control Chart (x-bar)

4.840

4.850

4.860

4.870

4.880

4.890

4.900

4.910

4.920

4.930

0 2 4 6 8 10 12 14 16

Observation

cm

Sample Mean

Upper Control Limit

Lower Control Limit

Center Line

Range Chart

0951.037.57.24 RD

0037.03 RD

Range Example

0

0.02

0.04

0.06

0.08

0.1

0.12

0 2 4 6 8 10 12 14 16

Sample Number

rang

e (c

m) Upper Control Limit

Center LineLower Control LimitSample Range

Warning Conditions

• Two successive points near limit

• Run of five above or below mean

• Trend• Erratic behavior

Process Control for AttributesProportion defective:

Number of defects per unit:

pp pn

( )1

UCL p

LCL pp p

p p

3

3

UCL cc c 3LCL cc c 3

c c

P-Chart

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

observation

prop

ortio

n de

fect

ive

observation proportion defective

lower control limit

center line

upper control limit

Homework

• Chapter 11 – 4, 8, 9