Root Cause Analysis
DMAIC Model
© 2010 Board of Regents University of Nebraska
What Is It?
Finding the real cause of the problem and dealing with it
rather than simply continuing to deal with the symptoms.
If I have an unwanted situation which consumes resources
and tends to happen repeatedly it might be beneficial to
figure out what is really causing this situation to occur and
remove it so the situation does not occur again.
© 2010 Board of Regents University of Nebraska
Guidelines for
Root Cause Assessment
Like pulling weeds… unless we
address the root that causes the
problem, poor results will keep
coming back.
© 2010 Board of Regents University of Nebraska
Philosophy of Problem Solving
Each problem is an opportunity because it can tell a story
about why and how it occurred
The “true” problem must be understood before action is taken
Be relentless
Ask “Why” at least five times to search out the root cause
To do this well, we must be
Both focused and open-minded
Both patient and quick
© 2010 Board of Regents University of Nebraska
DMAIC - Model used in Business
and Industry
DMAIC refers to a data-driven quality
strategy for improving processes, and is
an integral part of a Quality Improvement
Initiative. DMAIC is an acronym for five
interconnected phases: Define, Measure,
Analyze, Improve, and Control.
© 2010 Board of Regents University of Nebraska
What is DMAIC?
1.
Define: Identify a problem where the solution is
unknown.
2.
Measure: Establish a baseline. What is the current
state and extent of the problem?
3.
Analyze: Narrow down causes from trivial many to
critical few.
4.
Improve: Identify a solution, test and pilot it, measure
the improvement.
5.
Control: Sustain the gains, lock down the improvement
into procedures.
© 2010 Board of Regents University of Nebraska
Define
Identify all major steps in the
process.
Use a Process Map or Flowchart.
© 2010 Board of Regents University of Nebraska
Class Exercise
Coffee Pot Exercise
Scenario:
We are going to look at the process of
making a pot of coffee and use Quality
Tools to improve that process
© 2010 Board of Regents University of Nebraska
What are the parts?
This is your coffee Maker
© 2010 Board of Regents University of Nebraska
The Inputs to Coffee
© 2010 Board of Regents University of Nebraska
Example: The Process of
Making Coffee
Want
Coffee
Step 3
Step 1
Step 2
Clean pot &
coffee area
Get a
filter
Insert filter
into filter
holder
Step 6
Step 7
Insert filter
holder into
coffee maker
Measure water
into coffee
maker
Step 5
Measure coffee
into filter
Step 4
Get out
coffee
Step 8
Put pot on
burner and
turn on coffee
maker
Step 9
Step 10
Step 11
Step 12
Coffee maker
working?
Coffee
done?
Pour cup of
coffee
Taste
coffee
Coffee
Ready
© 2010 Board of Regents University of Nebraska
Example: Lets Make Some Pasta
Analysis - If the pasta is of poor quality, where did
the process break down?
© 2010 Board of Regents University of Nebraska
The Whole Picture – Pasta Example
Input Critical Characteristics
Temperature @ Input
Fluoride Content
Purity
Hardness
Texture
Crunchiness
Buoyancy
Initial Weight
Outer Diameter
Conductivity
Size
Temperature
Temp. Increase Rate
Stability / Degree of
Temp.Fluctuation
KEY PROCESS INPUTS
Water
Raw
Pasta
Cooking
Pot
Range
Top
PROCESS
Making
Pasta
KEY
PROCESS
OUTPUT
Cooked
Pasta
Output Critical
Characteristics
Final Weight
Taste Ranking
Absorbency
Texture Ranking
Stickiness
Outer Diameter
Pasta tastes good
and looks good!
QUALITY DRIVERS
© 2010 Board of Regents University of Nebraska
Measure
Use Data Collection & Analysis tools:
Gather data about how often a
problem occurs.
Gather data about the type of
problem occurring.
© 2010 Board of Regents University of Nebraska
Analyze
Ask “WHY” at least five
times to search out the
ROOT cause.
© 2010 Board of Regents University of Nebraska
5 Whys: Relentless Root Cause
Why?
© 2010 Board of Regents University of Nebraska
Problem: Flat tire in garage
1. Why? Nails on garage floor
2. Why? Box on shelf split
3. Why? Box got wet
4. Why? Rain through hole in garage roof
5. Why? Rain happens *
*can’t control so go back to previous why and fix it
© 2010 Board of Regents University of Nebraska
Root Causes
& The
Jefferson
Memorial
Issue: The stones on the Jefferson Memorial are deteriorating badly.
Initial solutions: Replace the stones; keep visitors off stones.
Costly!!!
© 2010 Board of Regents University of Nebraska
Jefferson Memorial
Why is stones deteriorating worse than other memorials?
They must be washed more frequently
Why are they washed more frequently?
There is more bird droppings on this memorial
Why does this memorial have more bird droppings on it.
They appear to be attracted to the insects
Why is there more insects on this memorial?
The lights are on longer which attract the insects
Change the lighting schedule to match other memorials
© 2010 Board of Regents University of Nebraska
Improve
Create innovative solutions using
technology and discipline.
Improve the target process by designing
creative solutions to fix problems.
Develop a plan for implementation.
© 2010 Board of Regents University of Nebraska
Control
Control the improvements to keep the process
on the new course.
Prevent reverting back to the "old way”
Standardize the process to maintain the gain.
© 2010 Board of Regents University of Nebraska
Compare DMIAC and the
Scientific Method
Can you find similarities between the DMAIC model and the Scientific Method used in
classroom laboratory investigations?
© 2010 Board of Regents University of Nebraska
Process Flowchart
A diagram that uses graphic symbols to depict
the nature and flow of the steps in a process.
Benefits of using flowcharts
Promotes understanding of a process
Identifies problem areas and opportunities
for process improvement.
© 2010 Board of Regents University of Nebraska
Flowchart Assignment
Use the “Symbols Used in Flowcharts”
handout as a guide to create a process
flowchart for manufacturing a dog kennel
and determine what part of the process
needs to be changed to correct the
problem of the rusted dog kennel.
© 2010 Board of Regents University of Nebraska