Chapter 10 The Tools of Quality

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Chapter 10 - The Tools of Quality

• Ishikawas 7 Basic Tools of Quality 7 New Tools

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Topics

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Balancing Functional Needs

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Customer Focus

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Process Improvement Tools

• Ishikawas Seven Basic Tools of Quality
• And - Seven new tools for improvement (N7)

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Ishikawas 7 Process Improvement Tools

• Process maps or flowcharts
• Check sheets
• Histograms
• Scatter diagrams
• Cause-and-effect diagrams (Ishikawa/Fishbone)
• Pareto analysis (charts)
• Control charts

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1. Process Maps or Flowcharts

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1. Maps or Flowcharts (1)

• A picture of the process
• In fact, 2 pictures (different from text)
• First step is to create a map as it should be
• Second step is to create a map as the process
  actually exists is
• Compares and contrasts actual versus ideal flow
  of a process

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1. Maps or Flowcharts (2)

• Shows unexpected complexity, problem areas,
  redundancy, unnecessary loops, and where
  simplification may be possible
• Allows a team to reach agreement on process steps
  and identify activities that may impact
  performance
• Serves as a training tool

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Mapping or Flowcharting Steps

• Chart the process from the beginning using simple
  symbols
• Develop a general process map, then fill it out
  by adding more of sub-flow-diagrams
• Determine which steps add value to the process
  and which dont in an effort to simplify the
  work
• Before simplifying work, determine if the work
  really needs to be done in the first place

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Extended Process Mapping of Supply Chains

• Supplier process
• Receiving
• Internal Processes
• Shipping
• Customer service processes

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2. Check Sheets

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2. Check Sheets (1)

• Data gathering tools that can be used in forming
  histograms
• Can be either tabular or schematic
• Typically data (occurrences) recorded in classes
  or categories

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2. Check Sheets (2)

• Creates easy-to-understand data
• Builds, with each observation, a clearer picture
  of the facts
• Forces agreement on the definition of each
  condition or event of interest
• Makes patterns in the data become
• obvious quickly

xx xxxxxx x
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3. Histograms

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3. Histograms (1)

• Representation of data in a bar chart format
• Also used to observe the shape of data
• How is the data distributed?
• Often follows use of checksheet

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3. Histograms (2)

• Displays large amounts of data that are difficult
  to interpret in tabular form
• Shows centering, variation, and shape
• Illustrates the underlying distribution of the
  data
• Provides useful information for predicting future
  performance
• Helps to answer the question Is the process
  capable of meeting requirements?

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3. Rules for Histograms

• Width of histogram bars must be consistent
• Classes or categories must be
• mutually exclusive and all-inclusive or
• collective exhaustive
• Rule of thumb for number of classes
• 9- 16 observations 4 classes
• 17- 32 5
• 33- 64 6
• 65-128 7
• 129-256 8

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4. Scatter Diagrams

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4. Scatter Diagrams (1)

• Supplies the data to confirm a hypothesis that
  two variables are related
• Provides both a visual and statistical means to
  test the strength of a relationship
• Provides a good follow-up to cause and effect
  diagrams

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4. Scatter Diagrams (2)

• Sometimes used to identify indicator variables in
  organization
• Easy to develop using the charting facilities in
  spreadsheets packages such as Excel

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4. Scatter Diagram Example

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5. Cause and Effect Diagrams

• Also know as
• Ishikawa Diagrams or
• Fishbone Diagrams

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5. Cause and Effect Diagrams (1)

• Looks like the skeleton of a fish
• The head is effect or problem statement
• The ribs are the major cause categories
• Specific causes form smaller bones off the ribs

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5. Cause and Effect Diagrams (2)

• Lets a team focus on problem content, not on
  problem history or differing personal interests
  of team members
• Creates a snapshot of collective knowledge and
  consensus of a team builds support for solutions
• Focuses the team on causes, not symptoms

Effect
Cause
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5. Cause and Effect Diagram Steps

• State problem clearly in the head of the fish
• Draw the backbone and ribs
• Ask the participants to identify the major causes
  (categories) of the problem
• Continue to fill out the diagram asking Why?
  about each problem or cause
• It usually takes no more than five levels of
  questioning Five whys
• Identify core causes and set goals to address them

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6. Pareto Diagrams

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6. Pareto Diagrams (1)

• Based on the work of Vilfredo Pareto
• French-Italian sociologist, economist, engineer,
  philosopher (1848-1923)
• Known for study of income distribution
• Helped develop the field of microeconomics
• Generalized and popularized by Joseph Juran
• 80/20 rule 80 of problems from 20 of causes
• Separate important few from trivial many

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6. Pareto Diagrams (2)

• Helps a team focus on causes that have the
  greatest impact
• Displays the relative importance of problems in a
  simple visual format
• Helps prevent shifting the problem where the
  solution removes some causes but worsens others

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7. Control Charts

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7. Control Charts (1)

• Focuses attention on detecting and monitoring
  process variation over time
• Distinguishes special from common causes of
  variation
• Serves as a tool for on-going control
• Provides a common language for discussion process
  performance

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7. Control Charts (2)

• Used to determine whether a process will produce
  a product or process with consistent measurable
  properties
• Covered in Chapters 12 and 13

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Run Charts

• Monitors performance of one or more processes
  over time to detect trends, shifts, or cycles
• Allows a team to compare performance before and
  after implementation of a solution to measure its
  impact
• Focuses attention on truly vital changes in the
  process

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Seven New Tools (N7)

• GOAL/QPC (consulting company) recommends that
  the N7 tools be used in a Cycle of Activity

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N1. Affinity Diagram

• Developed by a team or group
• Hierarchy of ideas
• Identify problem
• Write down issues on card or Post-its
• Stick/tape on wall
• Members move cards into groups
• Complete when no one moves cards
• Draw affinity diagram

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N2. Interrelationship Diagraph

• Follows affinity diagram
• Ask What other issues are caused or influenced
  by this issue?
• Draw 1-way arrow from first issue to second
• Count number of arrows pointing to each note
• Identify the cards with the most issues as the
  key factors
• Draw a double box around key factors
• Brainstorm ways to address issues

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N3. Tree Diagram

• Useful in identifying the steps needed to address
  the given problem
• Looks like a work breakdown structure
• Follows affinity diagram
• Put most important issue card at the top
• Create goal statement
• Identify steps to reach goal
• Repeat at next level

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N4. Prioritization Grid

• Used to make decisions based on multiple criteria
• Assign percentages and weights to each criterion
• Rank them in order of weighted percentages

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N5. Matrix Diagram

• Similar to QFD
• Relationship scores
• Use of high, medium, and low importance
• Provides basis for brainstorming

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N6. Process Decision Program Chart

• Use to brainstorm possible contingencies
• Steps include
• Develop a tree chart, placing first level boxes
  in sequential order
• Moving the second level list implementation
  details at a fairly high level
• At the third level ask What could go awry?
• At the fourth level Brainstorm counter-measures
  to the third level
• Evaluate counter-measures

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N7. Activity Network Diagram

• Useful for project management
• Program Evaluation and Review Technique (PERT)
  and/or Critical Path Method (CPM) diagrams
• Covered in Chapter 11

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Summary Comment

• The Basic 7 tools and the New 7 tools are useful
  in their simplicity and power
• Cultural change is needed to ensure that
  implementation can be successful