THE 7 BASIC QUALITY TOOLS
Susan Batchilder
January 24, 2013
Group Activity:
WHAT’S IN YOUR TOOL BOX?
• What is the purpose of your personal
toolbox?
– cleaning, fixing, remembering, coaching,
etc…
• What’s in your personal tool box?
• When did you last use your tool box?
• Do you have a tool box for your job?
• What is the purpose of your tool
box for work?
QUALITY TOOLS
• Purpose: provide the means for making
decisions.
• No particular tool is mandatory, any
one may be helpful, depending on the
circumstances.
• 95% of a company’s problems can be
solved using these tools.
• These are basic tools designed for
simplicity.
• Only one requires any significant
training.
7 BASIC QUALITY TOOLS
• FLOW CHART
• CAUSE AND EFFECT DIAGRAMS
• CHECK SHEET
• HISTOGRAMS
• PARETO CHART
• SCATTER DIAGRAM
• CONTROL CHARTS
Question: Why do we use these tools?
QUALITY TOOLS CAN…
• Help to identify and prioritize problems
quickly and more effectively
• Assist with the decision making
process
• Simple but powerful tools for use in
continuous improvement activity
• Provide a vehicle for communicating
problems and resolutions through-out
the business
• Provide a way of extracting
information from data collected.
A Side Topic
STRATIFICATION
• The 7 Quality Tools are useful when collecting data of
daily activities and analyzing them to detect and solve
problems, and an important concept for data analysis
is STRATIFICATION.
• Stratification mean classification of data in to a couple
of layers, and each layer is a subset of the population.
• Through stratification different statuses from the same
data is retrieved.
• What layers are considered for data analysis is crucial
when identifying problems.
Example of Stratification
• Number of births per year
• Number of births by gender per year
• Number of births by mom’s economic status by
gender per year
• deliveries per week
• deliveries per day of the week per week
• deliveries by hour per day of week per week
• DANAGER: When using stratification ensure it is
value added
• Back to the 7 Quality Tools
FLOW CHARTS
• Purpose: Illustrates the steps in a process
• Uses:
– Analyzing a process (e.g. relating one setp in the process
to others)
– Initiate process improvements (e.g. non-value added
steps)
– Indicates where in the process to take measurements
and collect data
• DANGER: including assumed or desired steps
• Note: The utility of the chart will correlate directly to
its accuracy.
Example: Flow Chart
CAUSE AND EFFECT DIAGRAMS
• Purpose: to identify as
many possible factors
for an effect or problem
and sort the causes into
useful categories.
• When to use?
– Identifying possible
factors
– When team’s thinking
falls into a “rut”
• Fishbone (most
common)
– Generic categories:
Methods, Machines,
Materials, Manpower,
Measurement, Mother
Nature
HOW TO CREATE A FISHBONE
CAUSE AND EFFECT DIAGRAM
Manpower
Machines
Methods
Problem Statement
“Effect”
Management
Mother Nature
Measurement
Materials
Maintenance
CAUSE AND EFFECT DIAGRAMS
• Other fishbone categories:
– Plan, Policies, Procedures, Plant, People
– Customers, Suppliers, Shipping, Warehouse…
• 5 WHYS: a method for getting to the root cause.
– Can also be used during the construction of the fishbone
diagram.
• GROUP ACTIVITY TIME – Let determine the cause of a
particular problem. Please give me a problem
statement and we’ll use the 6M’s.
GROUP ACTIVITY TIME
Manpower
Machines
Methods
Problem Statement
“Effect”
Mother Nature
Measurement
Materials
CAUSE AND EFFECT DIAGRAMS
Now What?
• Categorize (e.g. not probable, probable, very probable)
• Regression analysis (requires in-depth training)
• Design of experiments (requires in-depth
training)
• Lets go back to our example and
determine what our next steps will be.
• Do you remember the first time you
heard about a check list with regards
to data collection?
Example of a Check List
CHECK SHEET
• WHAT: A structured and prepared form.
• PURPOSE: To collect and analyze data so
decisions can be based on facts
• WHEN:
– When data can be observed and collected by the
same person or at the same location.
– When collecting data on the frequency or pattern
of events, problems, defects, defect location,
defect causes, etc.
– When collecting data from a production process.
• Data can further be used to create a
histogram, bar chart and Pareto chart
A Check List Can Become …
A Bar Graph
HISTOGRAM
• WHAT: A frequency distribution bar graph
• USES:
– Illustrates how often each different value in a data set
occurs
– Allows us to make sense of data
– Allows use to see patterns that are difficult to see in
tables of numbers
• DANGER: Before making any conclusions from a
histogram, it must be confirmed the process was
operating normally during the time period being
studied
Language of Histograms
What do they tell us?
SCATTER DIAGRAM
• WHAT: Scatter diagram graphs PAIRS of
numerical data.
• PURPOSE: To look for a possible
relationship
• DANGER: Even if the scatter diagram
shows a relationship, do not assume
one variable causes the other. Both
variable may be influenced by a third.
Scatter Diagram Examples
Graph 1 – strong correlation (linear)
Graph 2 – moderate correlation
Graph 3 – no correlation
Also – quadratic, exponential,
sinusoidal, and others
PARETO CHART
• What: Bar graph organized with the longest bars on the
left and the shortest to the right
• Purpose: Problem identification tool --- Visually
depicts which issues are more significant
• Use when…
– Analyzing data about the frequency of problems/causes
in a process
– There are many problems/causes and there is a need to
focus on the most significant
– Analyzing broad causes by looking at their specific
components
– Communicating data to others
PARETO PRINCIPLE
20/80 RULE
• THE IDEA THAT 20% OF THE CAUSES
GENERATES 80% OF THE RESULTS
With the Pareto chart we are identifying
the “vital few” from the “trivial many”.
PARETO CHART EXAMPLE
CONTROL CHARTS
• What: A statistical graphical
representation used to study how a
process changes over time
• Purpose: To distinguish between
variation in a process resulting from
common causes, and variation
resulting from special causes.
• Data are plotted in time order.
• Graphs include a central average line, a
upper control limit line and a lower
control limit line determined from
historical data.
“Out of Control”
Types of Control Charts
• Variable (continuous data – measureable)
•
•
•
•
•
•
X-bar Chart (average)
R chart (range)
s chart (deviation)
X chart (single data point – individual)
Moving range chart
XmR (individual with moving range)
• Attribute (discrete data – count)
•
•
•
•
p chart (percentage of defective units)
np chart (number of defective units)
c chart (number of defects per unit)
u chart (average number of defects per unit)
WHICH CONTROL CHART DO I USE?
OTHER TOOLS
• 5 WHYs (previously mentioned)
• Brainstorming
• Time Line
• Fault Tree Analysis
• Process Analysis
5 WHY’S – an example
• Problem --- Why is memorial A
deteriorating faster than the other
memorials?
–
–
–
–
–
Why? –washed more frequently
Why? –more bird droppings
Why? –birds attracted to monument
Why? –more fat spiders around it
Why? –more tiny insects during evening
hours
– Why? –illumination attracts more insect
– Solution
• Illuminate an hour later in evening
5 WHYs
Process
Best Practice
PROBLEM
PROBLEM
WHY?
WHY?
WHY?
WHY?
WHY?
WHY?
WHY?
WHY?
WHY?
WHY?
WHY?
WHY?
WHY?
WHY?
WHY?
WHY?
WHY?
ROOT
CAUSE
MULTIPLE POTENTIAL ROOT CAUSES
BRAINSTORMING
Brainstorming
• Can be performed by an individual or a
group
• Classic Example – write down anything
that comes to mind
• Ask questions – 5 Whys
• Categorize – Fishbone
• Many others
TIME LINE
• A presentation of a
chronological sequence of
events along a drawn line
that enables the reader to
quickly understand
relationships relating to,
or limited by, time
• Lines are usually drawn
from left to right or top to
bottom
• Example --- murder
mysteries, time line of
events before and up to
the time of death
FAULT TREE ANALYSIS (FTA)
• WHAT
– A graphic
representation of the
major faults or critical
failures associated with
a product, the causes
for the faults, and
potential
countermeasures.
• WHY
– It helps to identify areas
of concern for new
product design or for
improvements of
existing products.
– It helps to identify
corrective actions to
correct or mitigate
problems.
FAULT TREE
FTA – When to use?
• Designing new products/services
• Dealing with identified problems in existing
products/services
• To optimize process features and goals
• To design for critical factors and human
error
• To help identify root causes of trouble
• To design remedies and countermeasures
FAULT TREE
PROCESS ANALYSIS
• An operation (e.g. business) is
composed of processes designed to
add value by transforming inputs into
useful outputs. Processes can have a
significant impact on the performance
of a business and process
improvements can improve
competitiveness.
• A process analysis is performed when
the process (as a whole or as a part)
needs to be better understood.
Process Analysis
• Processes are analyzed
to better understand
their:
– Activities
– Relationships
– Values of relevant
metrics
• Process analysis
generally involves the
following tasks:
• Defining process
boundaries
(input/output)
• Process flow diagram
• Determining capacity of
each step of process
• Identifying limiting
step(s)
• Using analysis to make
business decisions and
improvements
Process Analysis
– Performance Measurements •
•
•
•
•
Process Capacity
Capacity Utilization
Throughput rate
Throughput time
Process time
•
•
•
•
•
Idle time
Work In Process
Set-up time
Direct Labour Content
Direct Labour Utilization
DANGER WIL ROBINSON!
WHY DO TECHNIQUES FAIL?
• Problem solvers might question
themselves
– Am I using the tool correctly?
• Is there a misconception in using the
tools to find the root cause of
problems?
• Is there another technique to help me
go beyond the basic cause and effect
analysis and get better results when
investigating issues?
COMMON “DANGERS”
• Only tool
• Confirmation Bias
• Unable to go beyond current
knowledge
• Human Factors
• Single Cause
COMMON “DANGERS”
– Only Tool • Many believe cause and effect analysis
is the only, or preferred method to find
root causes
• Avoid this misconception
• You CAN modify approaches, and use
other tools alone or in combination
COMMON “DANGERS”
- Confirmation Bias -
• People hypothesize a familiar pattern
(answer), and tend to look for
information to confirm their conclusion
(bias).
• People tend to jump to conclusions
before all the data is collected and
analyzed
• People may subconsciously disregard
evidence that counters their conclusion
– or requires more resources to
investigate.
COMMON “DANAGERS”
- Current Knowledge -
• Sometimes it is difficult for people to
analyze problems beyond their current
knowledge and try to make the
problem fit inside their understanding
of the issue.
• Problem solvers must have knowledge
of all possible causes to be able to
reach an accurate conclusion.
COMMON “DANGERS”
- Human Factors • Generally human performance causes most problems, but most
problem solvers have no formal training in the science of
human error and human performance.
– Lack of…
• Communication, Knowledge, Teamwork, Resources,
Assertiveness, and Lack of Awareness,
– Also…
• Complacency, Distraction, Fatigue, Pressure, Stress, and
Norms
• Cookie Cutter Approach
– Tendency to play the blame game
– Blame it on either human error or lack of training or
insufficient training
COMMON “DANGERS”
- Single Cause -
• Root cause analysis stops once a single
cause is found
• Just like accidents, major problems are
usually the result of a sequence of
events containing multiple causal
factors.
• Single causal chain misconception
leads to missed opportunities to
improve performance
COMMON “DANGERS”
- Others • Improper use of deductive reasoning
• Lack of practical training / opportunity to
use
• Difficulty in trending results
• Tunnel vision
• Fuzzy haze
– When the brain automatically fills in the missing
information when is perceives something,
sometimes leading to misperceptions
• Results not repeatable
– Results vary based on the analysis
- What would you do differently? • Problem --- Why is memorial A deteriorating
fasters than the other memorials?
–
–
–
–
–
–
–
Why? –washed more frequently
Why? –more bird droppings
Why? –birds attracted to monument
Why? –more fat spiders around it
Why? –more tiny insects during evening hours
Why? –illumination attracts more insect
Solution
• Illuminate an hour later in evening
COMMON “DANGERS”
- Deteriorating Monument • There are many possible factors, and
our list presents a few possibilities to
demonstrate what could be missed
without fully understanding the
sequence of events before drawing
conclusions.
• Missing potential alternative can waste
efforts when fixing phantom problems
or pushing problems from one area
to another.
COMMON “DANGERS”
- Deteriorating Monument • SOMETHING TO PONDER…
– The solution of turning the lights on one
hour later in the evening reduced
deterioration by 90%
• BUT REMEMBER…
– Correlation does NOT
prove causation
COMMON “DANGERS”
- Deteriorating Monument • Was reduction really due to change in
lighting schedule or were there other
factors not accounted for…
– Aware of deterioration, cleaners were
more careful?
– Did a weather change shift insect
behaviour?
– Are deterioration measurements accurate?
– Did lighting change shift problem to
another monument?
FOR YOUR INFORMATION
FYI
7 NEW QUALITY TOOLS for…
• Innovating
• Communicating
• Planning
• Tools
–
–
–
–
–
–
–
Affinity diagrams (for brain storming)
Arrow diagrams (can be simple or used with CPM & PERT)
Matrix data analysis
Matrix diagrams
Program decision program charts
Relationship diagrams
Tree diagrams
FYI: QMS MATURITY LEVELS AND
QUALITY TOOLS
• Maturity Level:
– Low
• Most Useful Tools:
–
–
–
–
Seven basic tools
Audits
Cost of quality (COQ)
Statistical process control
(SPC)
• Description:
– There is no formal quality
system, or if one exists, it
is not practiced on a daily
basis. Customer
complaints and other
external failure costs are
high. The quality dept is
held responsible for
quality. There is little or no
formal continuous
improvement that involves
people who actually carry
out the work processes.
FYI: QMS MATURITY LEVELS AND
QUALITY TOOLS
• Maturity Level:
– Medium
• Most Useful Tools:
– Creativity tools
– Customer surveys
– Failure mode and
effects analysis (FMEA)
– Benchmarking
– Design of experiments
(DOE)
• Description:
– External failure costs
have been lowered, but
these is still a high rate
of internal failures.
Each dept accepts it role
in the quality
management system,
and improvement
projects involving
employees are frequent.
FYI: QMS MATURITY LEVELS AND
QUALITY TOOLS
• Maturity Level:
– High
• Most Useful Tools:
– Seven management
tools
– Employee surveys
– Quality function
deployment
• Description:
– Management systems
for areas such as
quality, safety,
environment and
finance are seamlessly
integrated and driven by
the organizational
strategy. All depts and
work processes monitor
their own performances
and implement daily
improvement aligned
with strategic direction.
POP QUIZ EVERYONE 
QUALITY TOOLBOX SUMMARY
The 7 Quality Tools are…
QUALITY TOOLBOX SUMMARY
• These are TOOLS, and not the only
tools
• They can be used alone or in
combination
• They can be used by the individual and
groups
• Generally, they do not require
mastership to be used
• And remember to “Document” them
– photos work great
7 QUALITY TOOLS
QUESTIONS?
Disclaimer: All of the information provided in this presentation was
obtained from various internet webpages.