- Total Quality Management (TQM) Defined
- Quality Specifications and Costs
- Six Sigma Quality and Tools
- Service Quality Measurement
Chapter 9.Six-Sigma Quality 2. TQM Defined
- Total quality managementis defined as managing the entire
organization so that it excels on all dimensions of products and
services that are important to the customer
- Two fundamental operational goals:
- Careful design of product or service
- Ensure consistent production of product or service
3. Philosophical Leaders of the Quality Movement
- Each has slightly different definitions of what quality is and
how to achieve it (see Exhibit 8.1), but they all had the same
general message:
- To achieve outstanding quality requires:
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- quality leadership from senior management,
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- total involvement of the workforce, and
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- continuous improvement based upon rigorous analysis of
processes.
4. Quality Specifications
- Design quality-Inherent value of the product in the
marketplace
- Conformance quality- Degree to which the product or service
design specifications are met
- Products can have high design quality but low conformance
quality, and vice versa
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- Related to conformance quality
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- Means the person who does the work takes responsibility for
making sure output meets specifications
- Bothdesign qualityandconformance qualityshould provide products
that meet customer objectives
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- This is often termed fitness for use
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- Entails identifying the dimensions of product (or service) that
the customer wants i.e., the voice of the customer
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- Developing a quality control program
5. Dimensions of Quality
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- Primary product or service characteristic
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- Added touches, bells and whistles, secondary
characteristics
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- Consistency of performance over time, probability of
failing
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- Characteristics of the human-to-human interface (speed,
courtesy, competence)
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- Sensory characteristics (sound, feel, look, and so on)
- Perceived quality (reputation)
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- Past performance and other intangibles (perceived quality)
6. Dimensions of Quality Examples 7. Costs of Quality (COQ)
Costs of inspection, testing, and other tasks to ensure that the
product or process is acceptable sum of all costs to prevent
defects Costs for defects incurred within the system: scrap,
rework, repair Costs for defects that pass through the system
External Failure Costs Appraisal Costs Prevention Costs Internal
Failure Costs Costs of Quality 8. Costs of Quality
- No matter what the quality is, it willcost $ ...
- So, the assumptions of cost of quality
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- Performance can be measured
- Discussthe "internal" and "external failure costs" for a high
end coffee house (e.g., Starbucks)
9. Six-Sigma Quality
- Six-sigma is a philosophy which reflects the goal of
eliminating defects in the products.
- Seeks to reduce variation in the processes that lead to product
defects
- The name, six sigma refers to the variation that exists within
plus or minus six standard deviations of the process outputs
- Statistically speaking a process in six-sigma control limits
will only produce 2 defects per billion units.
10. 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
- Firms striving to achieve six-sigma generally adopt DMAIC
cycle.
- DMAIC are the typical steps employed in continuous improvement
(a.k.a. Kaizen) concept whichseeks tocontinually improveall aspects
of production (parts, machines, labor, processes, etc)
- 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
11. Six Sigma Quality: DMAIC Cycle Cases/examples from
classmates 1. Define (D) 2. Measure (M) 3. Analyze (A) 4. Improve
(I) 5. Control (C) Customers and their priorities Process and its
performance Causes of defects Remove causes of defects Maintain
quality 12. Example to illustrate the process
- We are the maker of this cereal.Consumer Reportshas just
published an article that shows that we frequently have less than
15 ounces of cereal in a box.
- What is the critical-to-quality characteristic?
- The CTQ (critical-to-quality) characteristic in this case is
theweightof the cereal in the box.
13. Step 2 - Measure
- How would we measure to evaluate the extent of the
problem?
- What are acceptable limits on this measure?
- Lets assume that the government says that we must be within5
percent of the weight advertised on the box.
- Upper Tolerance Limit = 16 + .05(16) = 16.8 ounces
- Lower Tolerance Limit = 16 .05(16) = 15.2 ounces
- We go out andrandomlybuy 1,000 boxes of cereal and find that
they weight an average of 15.875 ounces with a standard deviation
of 0.529 ounces.
- What percentage of boxes are outside the tolerance limits?
14. Upper Tolerance = 16.8 Lower Tolerance = 15.2 Process Mean =
15.875 Std. Dev. = .529 What percentage of boxes are defective
(i.e. less than 15.2 oz)? Z = (x Mean)/Std. Dev. = (15.2
15.875)/.529 = -1.276 NORMSDIST(Z) = NORMSDIST(-1.276) = 0.100978
Approximately, 10 percent of the boxes have less than 15.2Ounces of
cereal in them! 15. Step 3 - Analyze - How can we improve the
capability of our cereal box filling process?
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- Line vibration impacts scale
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- Random delays in nozzle open/close
16. Step 4 Improve How good is good enough? Motorolas Six
Sigma
- Calibrate the equipment more frequently, upgrade process
- 6-sigma minimum from process center to nearest spec
17. Step 5 Control
- Statistical Process Control (SPC)
- Use data from the actual process
- Look at capability - is good quality possible
- Statistically monitor the process over time
18. Analytical Tools for Six Sigma and Continuous
Improvement:Flowchart 19. Analytical Tools for Six Sigma and
Continuous Improvement:Runchart Can be used to identify when
equipment or processes are not behaving according to specifications
MEASURE 0.44 0.46 0.48 0.5 0.52 0.54 0.56 0.58 1 2 3 4 5 6 7 8 9 10
11 12 Time (Hours) Diameter 20. Analytical Tools for Six Sigma and
Continuous Improvement:Checksheet Can be used to keep track of
defects or used to make sure people collect data in a correct
manner( MEASURE )
Monday 21. 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 the causes ( MEASURE ) Assy.
Instruct . Frequency Design Purch. Training Other 80% 22.
Analytical Tools for Six Sigma and Continuous Improvement:Histogram
Can be used to identify the frequency of quality defect occurrence
and display quality performance ( MEASURE) Number of Lots Data
Ranges Defects in lot 0 1 2 3 4 23. Analytical Tools for Six Sigma
and Continuous Improvement:Cause & Effect Diagram 24.
Analytical Tools for Six Sigma and Continuous
Improvement:Opportunity Flow Diagram IMPROVE Value added activities
(Vertical steps) vs.Non-value added activities (horizontal steps)
25. 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 26. Other Six Sigma Tools
- Failure Mode and Effect Analysis (FMEA) 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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- a.k.a. multivariate analysis (testing)
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- i.e., testing multiple independent variables (Xs) with respect
to a dependent variable (Y)
27. The Shingo System: Fail-Safe Design
- SQC methods do not prevent defects
- Defects arise when people make errors
- Defects can be prevented by providing workers with feedback on
errors
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- prevents workers from making errors
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- Gives rapid feedback of abnormalities to worker in time to
correct them
28. The Shingo System:Example Exhibit 8.10 Poka-Yoke Example
(Placing labels on parts coming down a conveyor) 29. ISO 9000
- Series of standards agreed upon by the International
Organization for Standardization (ISO)
- A prerequisite for global competition?
- ISO 9000 directs you to "document what you do and then do as
you documented."
- First party: A firm audits itself against ISO 9000
standards
- Second party: A customer audits its supplier
- Third party: A "qualified" national or international standards
or certifying agency serves as auditor
- Is it important for small or medium sized businesses to have
ISO 9000 certification?
30. External Benchmarking Steps
- Identify those processes needing improvement
- Identify a firm that is the world leader in performing the
process
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- Obviously not a direct competitor
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- Possibly from another industry
- Contact the managers of that company and make a personal visit
to interview managers and workers
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- Compare the results (performance of the processes)