Quality tools for process management

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Quality tools for process management

• MGT 600
• Dr. Coty Keller
• St. Josephs MS in Management

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Contents of this presentation

• How these concepts fit in the total quality
  framework
• 8 Cool tools
• Summary Conclusion

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How does this fit into the framework for total
quality?

• Leadership and strategic planning
• Management of
• Customer and supplier relationships
• Human resources
• Processes
• Data and information
• This presentation is about tools for managing
  processes, data information

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8 Cool tools for managing process

1. Cause-and-effect (fishbone),
2. Flow chart,
3. Check Sheet (checklist)
4. Pareto chart,
5. Bar chart (histogram)
6. Run (trend) chart,
7. Scatter diagram
8. Control chart (SPC chart)

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Fishbone (Cause Effect) Diagram

• Useful for any problem (the Head of the fish is
  the Problem) if everyone is involved
• Brainstorming by ALL concerned is essential
• Categorize by general potential causes (the
  Bones of the fish)
• Goal identify likely Specific causes (the Ribs)
  that can be attacked and corrected

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Cause-and-EffectDiagrams
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Checker Board Airlines
Personnel
Equipment
Passenger processing at gate
Aircraft late to gate
Late cabin cleaners
Other
Mechanical failures
Unavailable cockpit crew
Weather
Late cabin crew
Air traffic delays
Delayed flight departures
Late baggage to aircraft
Poor announcement of departures
Late fuel
Weight/balance sheet late
Late food service
Delayed check-in procedure
Contractor not provided updated schedule
Waiting for late passengers
Materials
Procedures
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Wellington Fiber Board Co.
Figure 6.5
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Cause Effect Diagram at SJC

• Find cure causes or bad SMACs
• Not looking for symptoms
• Get to likely specific causes

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How can you tell a good fishbone?

• Good ones are made by brainstorming that includes
  everyone
• Good ones have ribs (likely causes) that are
  specific enough so they can be attacked and
  corrected

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Process Flow Chart

• Often the first step to improving a process is to
  describe it
• Help you understand and agree
• Shows how it should work, versus how it does work
• Can help you find redundancy, inefficiencies and
  misunderstandings

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What makes a good flow chart?

• A good flow chart has a beginning and an end,
• It shows who does what, and
• How the decisions impact on the path the process
  takes.
• Look at the ones in chapter 4 of the text, as
  well as those on p. 103, 4 of the Walton book

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Flow charts should show who does what (Credit
Sharon McKiernan)
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Check Sheet (also called checklist) simple
way to gather and interpret data
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Pareto Charts

• Common graphic technique (lets do a Pareto)
• Way to sort the vital few from the trivial many
• Can help you determine priorities
• Checklist is one way to collect data for the
  Pareto chart

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Wellington Fiber Board Co.
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Bar Chart (histogram) shows how frequently
something occurs
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Run (trend) chart

• Simplest of tools
• Data plotted over time so you can look for trends
• We do it for sales per month and to watch our
  investments
• Useful anywhere including hospital emergency rooms

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Scatter Diagram(Picture credit Mark Milano)

• A way to explore the relationships between two
  variables, i.e.
• Workers training and number of defects
• Moisture content and durability
• Light levels and computer errors
• Employee job satisfaction and customer
  satisfaction

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Statistical Process ControlSPC Overview

• SPC is used to detect significant change and
  indicate need for corrective action
• Underlying concept from Deming
• Two types of measures means two kinds of control
  charts
• Simple process
• Deciding on spread between upper lower limits
• Relationship between control and capability

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Deming says

• Variation is the root cause of poor quality
• Common cause variation is due to causes that are
  routinely present in the system while special
  cause variation stems from causes that are
  significantly different from normal.
• Special causes must be identified and eliminated
  on a case-by-case basis (well-trained workers can
  do this using control chart methods).
• Common cause variation is inherent to the system
  and can be reduced only by improving aspects of
  the systems design (a responsibility of
  management).

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Theory Application

• Common causes are random, unavoidable. Their
  character (mean, spread, shape) do not change
  over time)
• Special or Assignable causes are those causes of
  variation that can be Identified and eliminated.
• It is important to be aware of any change in
  mean, shape or spread of process distribution,
  because it is a symptom that an Assignable cause
  has developed.
• SPC is used to detect significant change and
  indicate need for corrective action

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Two types of measures

• Variable measures
• measured on continuous scale like weight,
  diameter, time
• know by how much
• - precise measure needed
• usually use x bar and range charts

• Attributes
• Discrete unit, only 2 values yes, no good bad
• less effort, less cost, tells quickly if
  quality changed
• - but does not show by how much, needs more
  observation
• usually uses p chart

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Using Control Charts for Process Improvement

• Measure the process
• When problems are indicated, find the assignable
  cause
• Eliminate problems, incorporate improvements
• Repeat the cycle

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Control Chart Example
UCL
Nominal
Variations
LCL
Sample number
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The Spread is an Economic Decision

• The greater the spread UCL-LCL, the less likely
  an alarm for a process being out of control.
  Narrow spreads cause more alarms
• Two types of errors
• type I error process declared out of control
  when it really is okay
• type II error process in control when in fact it
  is not
• Two sigma spread (narrower than a three sigma
  spread)
• increases likelihood of type I error
• reduces chance of type II error

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How to decide on spread? Implications

• A manager who uses three-sigma limits is implying
  that the cost of searching for Assignable causes
  is relatively large compared to the cost of not
  detecting a shift in process average
• Mangers using two-sigma limits imply that the
  cost of not detecting a shift in the process
  average exceeds the cost of searching for
  Assignable causes

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Control (process variance) and Capability
(meeting design specs)

• SPC limits are NOT specifications
• Can be in control and not meeting specifications
• But you can use control charts to determine if
  you are within tolerances. Clue of not being
  capable tolerances are smaller than/inside
  control limits

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SPC highlights

• Control charts stop people from chasing down
  causes
• The formula for control limits is designed to
  provide an economic balance between searching too
  often for special causes when there are none and
  not searching when a special cause may be found

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SPC highlights -2

• Do not confuse control limits with specifications
• Common causes (variations in workers ability,
  clarity of procedures, capability of systems and
  equipment, etc) can only be changed by management
• Control charts can let you immediately detect
  when something goes wrong a Special or
  Assignable cause.

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SPC highlights - 3

• Special causes (machine malfunctions, an
  untrained worker is put on the job, defective
  material arrives from the vender) show up on
  control charts as points outside the limits
• Once a system is in control, control charts can
  allow workers to record data and take action
  immediately when something goes wrong.
• A point need not be outside limits to indicate
  action (abrupt shifts or trends within limits
  signal the need to investigate)

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Statistical Process ControlOur job is to
implement

• The worker requires only a knowledge of simple
  arithmetic to plot a chart. But he cannot by
  himself decide that he will use a chart on the
  job, and still less can he start a movement to
  use charts.
• It is the responsibility of management to teach
  the use of control charts on the job where they
  can be effective. (Deming)

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Variability

• Variation is central to Demings philosophy
• Variation will never be eliminated
• Effort to reduce variation, however, is to
  improve constantly and forever the system of
  production and service
• SPC is a neat aid to accomplishing this

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Summary Conclusion

• The 8 tools can should help you
• Manage processes, data information,
• Improve quality on your job