Introduction to Statistical Quality Control

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Introduction to Statistical Quality Control

• ?????? ?????????

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Learning Objective

• ????????????????????????? quality and quality
  improvement
• ???????????????????? quality ????????????? ???
• ??????????????????????????????????????????????????
  ???????????????????????????

3
???????????????/?????? ????????

• ?????????????????????????????????????
• ???????????????????????????
• ??????????????????
• P Productivity
• Q Quality
• C Cost
• D Delivery
• S Safety
• M Method, Management
• E Environment

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Definitions and Meaning of Quality

• ?????????????????????????? quality ???
  ??????????????????? ????????????????????? ???
  product ???? service ???????
• Quality ??????????????????????????????????????????
  ???? consumer ????????????? product ???? service
• Quality ??????????????????????????????????????????
  ????????????????????????????

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Definitions and Meaning of Quality

• ?????????????????????????????????????????????
  ???? ???????????????????????
  ?????????????????????????? ???
  ???????????????????????????? ???????
• ??????????????????????????????????? ??? ???????
  ??? ?????????????
• ???????????? ???????????????????????????????
  ????????????? ????????????????????? ???????????
• ????????????????????????????????????, ??,
  ????????????????????, ??????? ????????????????????
  ???? ???????

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??????????????????????????????????????????????????
???

• Consumer ???????????????????????????????????,
  ?????? ?????????????? ??????????????????????????
• ??????????? ??????? ?????????????????????
• ???????????? ??????? ?????????????????????????????
  ???

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1-1 Definitions and Meaning of Quality

• 1-1.1 The Eight Dimensions of Quality
• Performance
• (will the product do the intended job?)
• Reliability
• (how often does the product fail?)
• Durability
• (how long does the product last?)
• Serviceability
• (how easy is it to repair the product?)

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1-1 Definitions and Meaning of Quality

• 1-1.1 The Eight Dimensions of Quality
• Aesthetics
• (what does the product look like?)
• Features
• (what does the product do?)
• Perceived Quality
• (what is the reputation of the company or its
  product?)
• Conformance to Standards
• (is the product made exactly as the designer
  intended?)

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• This is a traditional definition
• ??????????????????????????????????????????????????
  ?????????????????????? ?????????? 2 ?????? ???
• Quality of design
• Quality of conformance

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Definitions and Meaning of Quality

• Quality of design
• Products ??????????????????????????? size
• ????????????????? Product, ??????????????????????
  Product ????????????? (??????????)appearance ???
  performance
• ????????????????????????????????????materials
  ???????????????????????????? Product.

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Definitions and Meaning of Quality

• Quality of conformance
• ??????? ????????????????? product
  ??????????????????????????????? design
  ?????????????
• Factor ????? ???????????????????????????????????
  Quality
• ???????????????? manufacturing processes

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Definitions and Meaning of Quality

• ?????????????????? Quality of design ??? Quality
  of conformance
• ???? ?????????????????????????????????????????????
  ???????????????????????????????
  ?????????????????????????????????????????????
  ??????????????????????????????????????????????????
  ??????? ???????
• ??????????????????????????????????????????????????
  ??????????????????????????????????????

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?????????????????????????????????????

• ??????????????????????????????????????????????????
  ????????????
• ??????????????????????????????????????????????????
  ? ??????????????????? (Control Charts)
• ?????????????? ??????????????????????
  ???????????????????????????????????????????????
  ??????????????????????????????????????????????????
  ????????????

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?????????????????????????????????????

• ??????????????????????????????????????????????????
  ????????????????????????????????????????
• ??????????????????????????????????????????????????
  ???????????????? ?????????????????????????????????
  ??????????????????????????????????????
• ??????????????????????????????????????????????????
  ??????????????????????????

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This is a modern definition of quality

• ?????????????? Quality ????????
  ??????????????????????????????????????????????????
  ??? variability ???????????????
• If variability characteristics of a product
  decreases, quality of product increases.

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The Transmission Example

• How did the Japanese do this?
• It leads to the following definition of quality
  improvement

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• The transmission example ???????????????????????
  ?????????? Quality improvement
• ?????????????? quality improvement ???
  elimination of waste.

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Quality Engineering Terminology

• Parameter ?????????? ?????????????????????????????
  ???????? consumer ??????????? critical-to-quality
  ?????????????
• Physical length, weight, voltage, viscosity
• Sensory taste, appearance, color
• Time Orientation reliability, durability,
  serviceability

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Quality Engineering Terminology

• Quality Engineering
• Set ???????????????????, ?????????????????????????
  ????????? ????????????????????????????????????????
  product ??????????????????????
• ?????????????????? product ??????????? match
  ?????????? customer ??????? ??? variability
• ?????????????????? variability ??? material,
  performance, operator ?????????????
  ????????????????????????????? quality improvement

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Quality Engineering Terminology

• ????????????? statistical method
  ????????????????????????????? ????????? data
  ???????????????????????? ??? 2 ?????
• Attributes data (????????????????) ????????????
  Countable Data ??? ???????????????????????????????
  ????????????????????????? ???????? ????
  ?????????????? ??????????????
• Variable data (????????????????)????????????
  Measurable Data ???? length, voltage, or
  viscosity

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Terminology

• ?????????????????? ?????????????????????????
  Specifications(?????????????)
• ??????????????? product ???? specification
  ????????? component, subassembly ???? final
  product
• ???????????????????????????????????????????????
  nominal or target value ??????????????????????????
  ??????????????
• ??????????? ?????????????????? product
  ????????????? target value ???? product
  ?????????????????????????????? ????
  ?????????????? product

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Terminology

• ??????????? specification limit
• Lower specification limit
• Upper specification limit
• Nonconforming product ????????????????????????????
  ?????? material, process ???? part ????? ???????
  ???????????? component ???? product
  ?????????????????????
• Nonconforming ??????? fail ??????? specification
  ??? product

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Terminology

• Nonconforming ????????????????????????????????????
  ??????????????????
• Nonconforming ???????????????????? Defect product
  ??? defect ?????????????????????????????????
  ????????????????????????????? product
  ????????????????

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Statistical Methods

• Statistical process control (SPC)
• Control charts, plus other problem-solving tools
• Useful in monitoring processes, reducing
  variability through elimination of assignable
  causes
• On-line technique
• Designed experiments (DOX)
• Discovering the key factors that influence
  process performance
• Process optimization
• Off-line technique
• Acceptance Sampling

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Statistical Methods
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Statistical Methods
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Statistical Methods