8. Statistical Methods for Quality
Control and Improvement
Three major areas:
Statistical process control (SPC)
Design of experiments (DOE)
Acceptance sampling
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9. Statistical Process
Control (SPC)
Control charts
are used for
process
monitoring and
variability
reduction.
SPC is an on-line
quality control
tool. (線上的品管
工具)
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10. Design of Experiments
Experimental design is an approach
to systematically varying the
controllable input factors in the
process and determine the effect
these factors have on the output
responses.
Experimental designs are off-line
quality tools.(線外的品管工具)
Crucial for variability reduction.
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18. Legal Aspects of Quality
The re-emergence of quality assurance as
an important business strategy is in
part a result of
1. Consumerism
2. Product Liability
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20. Legal Aspects of Quality—
Consumerism
The explosion in the number
of products.
Consumer tolerance for minor
defects and aesthetic
problems has decreased
considerably.
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22. Legal Aspects of Quality —
Product Liability
The legal obligation of manufacturers
and sellers to compensate for injury or
damage caused by defective products.
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24. Principles of Strict Liability
A strong responsibility for both
manufacturer and merchandiser,
requiring immediate responsiveness
to unsatisfactory quality through
product service, repair, or
replacement of defective product.
All advertising statements must be
supportable by valid company quality
of certification data.
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29. Quality Trilogy (Joseph M. Juran)
Quality Planning Quality Control
– Evaluate actual product
– Determine who the performance
customers are – Compare actual
– Determine the needs of performance to product
the customers goals
– Act on the difference
– Develop product
Quality Improvement
features that respond to
– Establish the
customers’ needs infrastructure
– Develop processes able – Identify the improvement
to produce the product projects
features – Establish project teams
– Transfer the plans to – Provide the teams with
resources, training and
the operating forces motivation to diagnose the
causes stimulate remedies
establish controls to hold
the gains
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41. ISO 9000認證體系
認證機關
Accreditation Body
登
錄
登
認 錄
驗證機構 證
訓練機構
Certification Body/
Training Body
Registration Body
驗 僱 訓 評
證 用 練 核
評審員/稽核員
各企業/公司
Assessor/Auditor
品質管理 41
42. The Malcolm Baldrige National
Quality Award，MBNQA1
1987年8月20日創立
施行者： The National Bureau of
Standards and Technology，NIST)
目的
– 促進瞭解市場需求
– 改善競爭力
– 分享在良好策略上的成功經驗
– 瞭解成功策略的由來與益處
品質管理 42
44. MBNQA 獎項準則架構1
Organization Profile
Environment, Relationships, and Challenges
2 5
Strategic Human
planning resources
7
1
Business
Leadership
results
3 6
Customer and Process
Market focus management
4
Information and analysis
品質管理 44
54. The Link Between Quality
and Productivity
Effective quality improvement can
be instrumental in increasing
productivity and reducing cost.
The cost of achieving quality
improvements and increased
productivity is often negligible.
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59. 查檢表(Check Sheet)
Useful for collecting historical or
current operating data about the
process under investigation.
種類
– 記錄用查檢表
– 查檢用查檢表
功用
– 作為日常管理
– 作為特別調查
– 調查結果的記錄保存
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64. 特性要因圖
(Ishikawa diagram—Kaoru Ishikawa)
Once a defect, error, or problem
has been identified and isolated
for further study, potential causes
of this undesirable effect must be
analyzed.
Cause and effect diagrams are
sometimes called fishbone
diagrams because of their
appearance
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66. Construct a Cause-and-Effect Diagram
1. Define the problem or effect to be analyzed.
2. Form the team to perform the analysis.
Often the team will uncover potential causes
through brainstorming.
3. Draw the effect box and the center line.
4. Specify the major potential cause categories
and join them as boxes connected to the
center line
5. Identify the possible causes and classify
them into the categories in step 4. Create
new categories, if necessary.
6. Rank order the causes to identify those that
seem most likely to impact the problem.
7. Take corrective action.
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68. 散佈圖
The scatter diagram is a plot of
two variables that can be used to
identify any potential relationship
between the variables.
The shape of the scatter diagram
often indicates what type of
relationship may exist.
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69. The Frequency Distribution
and Histogram(直方圖)1
間斷分配
– 蒐集資料
– 排序
– 編製次數分配表
– 繪直方圖
次數直方圖
相對次數直方圖
累積次數直方圖
相對累積次數直方圖
品質管理 69
70. The Frequency Distribution
and Histogram(直方圖)2
連續分配 – 定組距(i)
– 蒐集資料 i=R/K
取奇數，可使組中點與
– 排序
數據有相同之小數點位
– 定全距：R=Xmax-Xmin 數
– 定組數(k) – 定組限與組
K=(N)1/2 – 界定組中點
史特吉斯(Sturgis)法則：
– 編製次數分配表
K=1+3.322logN
經験值 – 繪直方圖
品質管理 70
