MANAGING QUALITY
SIX SIGMA
9-2
Learning Objectives
• Define the term quality.
• Explain why quality is important and describe the consequences of poor quality.
• Identify the determinants of quality.
• Describe the costs associated with quality.
• Describe some of the current quality awards.
What is Quality?
Quality
A term used by customers to describe their general satisfaction with a service or product.
FOUNDATIONS OF MODERN QUALITY MANAGEMENT: THE GURUS
WALTER SHEWART
• Pioneer in the field of quality control
• Known as “Father of statistical quality control”
• Develop methods for analyzing the output of industrial processes to determine whether corrective action is necessary
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FOUNDATIONS OF MODERN QUALITY MANAGEMENT: THE GURUS
W.EDWARDS DEMING• Bringing about improvements in product
and service quality by reducing uncertainty and variability in goods and services design and associated processes (the beginning of his ideas
in 1920s and 1930s)• Higher quality leads to higher productivity
and lower costs.• Deming’s “Chain Reaction” theory• “14 Points” management philosophy.• Deming Cycle – Plan, Do, Study, and Act.
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FOUNDATIONS OF MODERN QUALITY MANAGEMENT: THE GURUS
Others:
• Armand Feigenbaum
• Philip B. Crosby
• Kaoru Ishikawa
• Genichi Taguchi
• Taichi Ohno & Shigeo Shingo
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Key Contributors to Quality Management
Contributor
Deming Juran Feignbaum Crosby Ishikawa Taguchi Ohno and Shingo
Known for
14 points; special & common causes of variation Quality is fitness for use; quality trilogy Quality is a total field Quality is free; zero defects Cause-and-effect diagrams; quality circles Taguchi loss function Continuous improvenment
Q u a lit y
Understanding Quality
Quality can be a CONFUSING CONCEPT…
WHY??
Customers’ expectations
for the product or
service
Customers’ perceptions
of the product or
service
Gap
Perceived quality is poor Perceived quality is good
Expectations > perceptions
Expectations = perceptions
Expectations < perceptions
Perceived quality is governed by the gap between customers’ expectations and their perceptions of the
product or service
Perceived quality is governed by the gap between customers’ expectations and their perceptions of the
product or service
Gap
Perceived quality is acceptable
Customers’ expectations
for the product or
service
Customers’ perceptions
of the product or
service
Customers’ expectations
for the product or
service
Customers’ perceptions
of the product or
service
INSIGHTS ON QUALITY MANAGEMENT: defining quality
PRODUCT QUALITY Performance Aesthetics Special Features Conformance Reliability Durability Perceived Quality Serviceability
PRODUCT QUALITY Performance Aesthetics Special Features Conformance Reliability Durability Perceived Quality Serviceability
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INSIGHTS ON QUALITY MANAGEMENT: defining quality
SERVICE QUALITY
Convenience Reliability Responsiveness Time Assurance Courtesy Tangibles
SERVICE QUALITY
Convenience Reliability Responsiveness Time Assurance Courtesy Tangibles
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9-12
Challenges with Service Quality
• Customer expectations often change
• Different customers have different expectations
• Each customer contact is a “moment of truth”
• Customer participation can affect perception of quality
• Fail-safing must be designed into the system
INSIGHTS ON QUALITY MANAGEMENT: defining quality
The dimensions of both product and service quality establish a conceptual framework for thinking about quality.
QUALITY – must be stated in terms of specific, measurable characteristics.
The dimensions of both product and service quality establish a conceptual framework for thinking about quality.
QUALITY – must be stated in terms of specific, measurable characteristics.
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DETERMINANTS OF QUALITY
The degree to which a product or a service successfully satisfies its intended purpose has 4 primary determinants
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9-15
Determinants of Quality
Service After
delivery
Ease ofuse
Conforms to design
Design
9-16
Determinants of Quality
• Quality of design– Intention of designers to include or exclude
features in a product or service
• Quality of conformance– The degree to which goods or services
conform to or achieve the intent of the designers
• Fitness for Use: the ability of a good or service to meet customer needs.
• Quality of Conformance: extent to which a process is able to deliver output that confirms to design specifications.
• Specifications: targets and tolerances determined by designers of goods and services.
Quality in Operations
Quality in Operations
• Quality Control: means of ensuring consistency in processes to achieve conformance.
• Service Quality: consistently meeting or exceeding customer expectations and service delivery system performance criteria during all service encounters.
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The Consequences of Poor Quality
• Loss of business
• Liability
• Reduced productivity
• Increased costs
Costs of Quality
• Prevention Costs
• Appraisal Costs
• Internal Failure Costs
• External Failure Costs
QUALITY MANAGEMENT SYSTEM
• Quality management refers to systematic policies, methods, and procedures used to ensure that goods and services are produced with appropriate levels of quality to meet the needs of customers.
• Organizations today integrate quality principles into their management systems, using tools such as Total Quality Management (TQM), Six Sigma, and Lean Operating Systems.
Total Quality Management
TQM
A philosophy that stresses principles for achieving high levels of process performance and quality.
Six Sigma
• Six Sigma is a business improvement approach that seeks to find and eliminate causes of defects and errors in manufacturing and service processes by focusing on outputs that are critical to customers and results in a clear financial return for the organization.
• Used by companies including Motorola, Allied Signal, Texas Instruments, and General Electric.
Six Sigma Approach
X XX X
XX
XX X
XXXXX XXX
Process average OK;too much variation
Process variability OK;process off target
Processon target withlow variability
Reducespread
Centerprocess
X
X
X
X
X
X X
X
X
The plan–do–check–act (or ‘Deming’) improvement cycle,and the define–measure–analyze–improve–control
(or DMAIC) ‘six sigma’ improvement cycle
Define
Measure
AnalyzeImprove
ControlPlan Do
CheckAct
Plan
Six Sigma’s DMAIC Process
Define: identify customer and priorities, identify and define a suitable project, identify CTQs (critical to quality characteristics).
Measure: determine how to measure the process, identify key internal processes that influence CTQs.
Analyze: determine likely causes of defects and understand why defects are generated by identifying key variables that cause process variation.
Six Sigma’s DMAIC Process
Improve: identify means to remove defects, confirm key variables, modify the process to stay within acceptable range.
Control: determine how to maintain improvements, put tools in place to ensure that key variables remain within acceptance ranges under the modified process.
The “Seven QC Tools”
1. Flowcharts: process mapping to identify the sequence of activities or flow of materials/information in a process.
2. Run Charts and Control Charts: line graph with data plotted over time; control charts include control limits.
3. Checksheets: simple tools for data collection, ensure completeness.
4. Histograms: graphically represents frequency of values within a specified group.
The Structure of a Control Chart
Exhibit 7.7 Defective Item Checksheet
Source: K. Ishikawa, Guide to Quality Control (Tokyo: Asian Productivity Organization, 1982), p. 33.
The “Seven QC Tools”
5. Pareto Analysis: separates vital few from the trivial many causes; provides direction for selecting project improvement.
6. Cause-and-Effect Diagrams: represents chain of relationships; often called a fishbone diagram.
7. Scatter Diagrams: graphical component of regression analysis.
Use of Pareto Diagrams for Progressive Analysis
Source: Small Business Guidebook to Quality Management, Office of the Secretary of Defense, Quality Management Office, Washington, DC (1988).
Cause-and-Effect (Fishbone) Diagram for Hospital Emergency Admission
1. Flowcharts: process mapping to identify the sequence of activities or flow of materials/information in a process.
2. Run Charts and Control Charts: line graph with data plotted over time; control charts include control limits.
3. Checksheets: simple tools for data collection, ensure completeness.
4. Histograms: graphically represents frequency of values within a specified group.
5. Pareto Analysis: separates vital few from the trivial many causes; provides direction for selecting project improvement.
6. Cause-and-Effect Diagrams: represents chain of relationships; often called a fishbone diagram.
7. Scatter Diagrams: graphical component of regression analysis.
The Deming Cycle
•Plan: study current situation•Do: Implement plan on trial basis•Study: determines if trial is working correctly•Act: standardize improvements
Kaizen: focuses on small, gradual, and frequent improvements over the long term with minimum financial investment and with participation by everyone in the organization.
Poka-Yoke (Mistake-Proofing): an approach for mistake-proofing processes using automatic devices or methods to avoid simple human error.
Poka-Yoke Examples
• Machines have limit switches connected to warning lights that tell the operator when parts are positioned improperly on the machine.
• Fast food restaurants used automated French frying machines that can only be operated one way and the French fries are prepackaged and the equipment automated to reduce the chance of human error.