Root Cause Elimination
Extract
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Decision Matrix – Who should do
inspections?
GROUPS
1. Operator
2. Area Maintenance
3. In house maintenance expert
4. Outside expert
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In cooperation with
Root Cause Methods and Tools
There‘s a right tool for every task
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In cooperation with
Root Cause Tools and
Documentation Methods
Methods and Tools Discussed
– 6 Thinking Hats
– Logic Diagrams
– Fishbone / Ishikawa Diagrams
– Statistical Methods and Control Charts
– Mind Mapping
– FMEA / FMECA Analysis
– 5 Why’s
– Pareto Analysis
– Cause-Effect Mapping
– Timelines
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In cooperation with
Interaction Between Methods
and Tools
• The tools discussed herein can be combined to form a complete root
cause toolbox rather than relying on a single method which only spans a
part of the process.
• Should be draw up a chart displaying the breadth each method or tool
spans we may come up with the following:
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Interaction Between Methods
and Tools
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6 Thinking Hats
• A method for meeting management to bring about a
structured way to brainstorming sessions.
• Listed in several books by Edward De Bono
• The 6 Hats can metaphorically be used to signify different
moods / characteristics in thinking or be taken literally,
depending on the wishes of the meeting facilitator.
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6 Thinking Hats
• The White Hat neutral, • The Red Hat represents
and objective. Take time Feelings. Take time to
to look at the facts and listen to your emotions,
figures. Simulate your intuition.
Computer.
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6 Thinking Hats
• The Green Hat is grass, • The Yellow Hat is sunny
fertile and growing. and positive. Take time
Take time to be creative to be hopeful and
and cultivate new ideas. optimistic. Look at all
positive sides and
opportunities.
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6 Thinking Hats
• The Black Hat is critical • The Blue Hat is
and pessimistic. Take facilitation and. Take
time to look at all time to look from a
problems, flaws and higher and wider
potential dangers fail. perspective.
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In cooperation with
Mind Mapping - Concept
• Predominantly a documention method for the
brainstorming part of a root cause analysis.
• The mapping method is used to represent words,
tasks, ideas or other items linked to and arranged
around a central keyword or idea.
• Mind maps help visualize, sort and structure
information that arrives through a brainstorming
sessions.
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In cooperation with
Mind Mapping
Guidelines
• Start with the main problems / idea in the middle
• Use 1-3 colors (one for each main spur from the center)
• Use a lot of imagery throughout the mind map to reduce
words
• Use keywords with the imagery
• All lines connecting ideas should be connected and lead into
the central problem
• Try to keep the mind map clear by spreading the initial
concepts out enough to allow hierarchies to be built radially
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In cooperation with
Mind Mapping
Personal Evaluation
• Gets confusing due to the unorganized manner the maps get
created in
• Software helps greatly with executing mindmapping in
brainstorming sessions but takes away some creativity
• Easy to get locked up in particular tangents if used by itself.
• Good if combined with other methods such as the six thinking
hats
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Logic Tree
Rules
• Is a visual method for drawing up the relationsship
between causes and effects
• Like a family tree is looks back in time for these
relationsships
• Boolean And / Or logic is displayed when more than
one factor can take part in forming a effect
• Logic trees are drawn from the top down in portrait
mode
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Logic Tree
Example
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Logic Tree
Example
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Logic Tree
Personal Evaluation
• Quick overview of investigation work that has
been done
• Very easy to follow cause and effect
• Not conducive for use on the plant floor
• Charts become very big sometimes
• Little room for writing information
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Fishbone / Ishikawa Diagrams
• Documentation method meant to sort causes of an event into categories.
• Sometimes also called Cause-Effect diagrams (different from Cause-Effect
mapping)
• The number and types of categories used varies by industry.
• Manufacturing:
– 4M‘s or 6M‘s
• Service Industries:
– 8P‘s or 4S‘s
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Fishbone/Ishikawa
Manufacturing 4M/6M
First 4M‘s
• Machinery (Technology)
• Methods (Inspections and Processes)
• Materials
• Manpower / Mindpower (Kaizen´s, Suggestions)
Additional 2M‘s may be used:
• Money
• Milieu (Enviroment)
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Fishbone/Ishikawa
Service 8P Categories
• Product
• Price
• Place
• Promotion
• People
• Process
• Physical Evidence
• Productivity and Quality
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Fishbone/Ishikawa
Service 4S Categories
• Surroundings
• Suppliers
• Systems
• Skills
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Fishbone/Ishikawa
Additional Categories
• Additional categories or different names may be used, e.g.
– Personnel instead of Manpower
or
– Environment instead of “Milieu”
• Some other categories that can also be seen:
– Maintenance (Which otherwise can be broken into the 4M´s/6M´s)
– Money [Power]
– Management (Which can otherwise be included in Manpower or
Methods)
– Measurements (Which can be included in Methods)
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Fishbone/Ishikawa
Example
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Fishbone/Ishikawa
Example
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Fishbone/Ishikawa
Personal Evaluation
• Cluttered
• Little room to write
• Cannot see cause and effect easily
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FMEA / FMECA Analysis
• FMEA´s and FMECA´s are two separate, but very
closely related methods for use in Enginering and
Root Cause.
– FMEA
• Failure Modes and Effects Analysis
– FMECA
• Failure Modes and Effects Criticality Analysis
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Difference between FMEA and
FMECA
• FMEA´s are meant to explore and document which failures can appear in
a system or equipment and which effect each failure will have.
– This creates a Cause-Effect relationsship only for each Failure Mode.
• FMECA´s take the FMEA and add on a Criticality Analysis for each Failure
Mode using:
– Probability/Risk factor, usually in the range of 1-10 or 1-4
– Consequence/Severity factor, usually in the range of 1-10 or 1-4
– Detectability/Confidence factor, usually in the range of 1-10 or 1-4
• The goal of the FMECA is to try to reach a objective conclusion as to which
failure modes constitute the greatest threat to the process, organization of
equipment being analysed.
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FMEA / FMECA -
Personal Observations
• FMECA‘s most often more valuable than only FMEA‘s.
• Can be large and difficult to get a comprehensive handle on due vast
number of failure modes which can occur.
• Work‘s well as supporting documentation on larger engineering or root
cause studies, where the methods are used after brainstorming methods
and Cause-Effect mapping.
• In such cases FMEA/FMECA‘s do not serve as total oversight
documentation for the project, but merely document to further details
what‘s described in the Cause-Effect map.
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5 Why´s
Concept
• 5 Why‘s is a method for asking questions to explore the causes of a event.
• The main idea of the method is that asking the question Why 5 times you
will get to a cause that will be far enough upstream in the Cause-Effect
relationsships to give a broad solution for the current problem and others
possibly related
• Despite the method‘s name it is not limited to only asking Why 5 times. 6-
7 iterations are common.
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5 Why´s
Concept
• Starting with the problem you have (trigger)
you ask why and take the most obvious cause
and then ask why that happened.
• Re-iterating the above questions is to bring
you to a reasonable and satisfying conclusion.
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5 Why´s
Example
• Problem – Product mix has too low contents of
chlorine
– Why 1: Inadequate flow from Chlorine Pipes
– Why 2: Chlorine Metering Pump is not working properly
– Why 3: Impeller is worn
– Why 4: Pump seems to have had cavitation
– Why 5: Because of supply inlet pipe restrictions
– Why 6: Because the inlet valve was partially closed
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5 Why‘s
Rules
• The troubleshooter must still respect the
thinking methods and avoid assumptions,
logic traps and only step past one Why at a
time.
• Only when satisfied that he‘s got a good why
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5 Whys
Methodology
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5 Why‘s
Applied
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5 Why’s
Personal Evaluation
• The 5 why’s over simplifies to be useful in an
investigation.
• The documentation method doesn’t “push” one of
the key points in RCE: Come up with many possible
causes. The layout makes your mind try to only drill
down rather than looking at many possibilities.
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In cooperation with
Pareto Analysis
• Pareto Analysis is a statistical technique aimed solely at limiting the
number of tasks to focus on.
• Pareto Analysis aims at focusing on those tasks which will have the largest
effect on a system, process or equipment.
• The name comes from the Pareto Principle, also known as the 80-20 rule
(sometimes expanded into 70-30).
• The principle states that for many problems roughly 80% of the effects
arise from only 20% of the causes.
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Applying Pareto Analysis
There are 8 steps involved in a Pareto Analysis
1. Create a table listing all causes in a separate line and their individual effect-
share as a percentage of the total effects.
• Example: 6 Causes cause 20 hours of downtime. Cause A is responsible for 20%
hrs, cause B for 5%, cause C for 40%, cause D 15% etc.....
2. Arrange the rows in a decreasing order of importance
• The cause which has the highest number of effects appears at the top and the one
with the lowest appears at the bottom.
3. Add a cumulative percentage column to the table
4. Plot with causes on the x-axis and effects on the y-axis
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In cooperation with
Applying Pareto Analysis
There are 8 steps involved in a Pareto Analysis
5. Join the above points to form a curve
6. Plot a bar-graph on the same graph with causes on the x-axis and effets on
the y-axis.
7. Draw a line at 80% on the y-axis (Y=80%) By drawing a line down to the x-axis
from where this y-axis line intersects the curve you will be able to decide
which causes to focus on, as those will be the ones that are to the left of the
line you drew down to the x-axis.
8. Review the chart to make sure that it is correctly drawn.
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Pareto Analysis – Example
Pareto for Unique Work Orders to Equipment
(Accumulative percentage of total work orders vertical, accumulative number of work orders
horizontal)
Pareto of Work Order Value Pareto of Number of Work Orders
100.00%
90.00%
80.00%
70.00%
60.00%
50.00%
80% of the number of work 80% of work order cost is 50% of total non-rep WO
40.00% orders is written to 29% of written to 17% of this cost is spent on just 108 of
30.00% the equipment for which at equipment over 15,000 equipment
least one WO has been items
20.00% closed
10.00%
0.00%
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In cooperation with
Cause-Effect Mapping
Scalability
• There is no theoretical limit to the size of the cause map
• It is only a tool
• When deciding how far back to go, or how specific to be, rationality has to
be applied weighing in:
– Scale of effects of the problem being mapped ($10 problem, $1 Million
problem, $1 Billion problem?
• As most root cause investigations involve teams the job of setting practical
boundaries must fall on the facilitator, or team leader
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In cooperation with
Cause-Effect Mapping
Identify a Impacted Goal Safety Goal
Impacted
• Number of goals: Regulatory
Goal
– More?
Impacted
Customer
• Goals can be something we self choose for business Goal
Impacted
reasons, or something we must do because of regulation
Production
Goal
• Start mapping from a single impacted goal. You can always Impacted
add a single one later Property
Goal
Impacted
Labor
Goal
Impacted
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In cooperation with
Cause-Effect Mapping
First Cause-Effect Steps
• Remember to confine yourself to clearly marked single Cause-Effect
relationsship at a time.
• Do not worry about linking in all factors that can impact a failure at
the same time
• If a possible failure mode can be ruled out on the spot, it would be
beneficial to include it on the map. But mark it as having been ruled
out because of....
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Cause-Effect Mapping
Assign For Verification 1/2
• Use a red strikethrough to rule out the Cause-Effect relationships
that you know did not happen
• Use the red Evidence box to give links to evidence that something
did, or did not, happen Evidence:
• At some point the groups knowledge will be exhausted
• Investigations cannot stop there
• Assign specific Cause-Effect relationsships which you cannot prove,
or disprove on the spot to individuals
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In cooperation with
Cause-Effect Mapping
Assign For Verification 1/2
• At the end of your meeting decide when the next meeting is to be
held and expect progress to be reported on the assigned Cause-
Possible
Effect relationsship
Solutions:
• This responsibility falls on the facilitator Evidence:
• If possible solutions can be identified indicate those can be found
in the Possible Solutions box
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In cooperation with
Cause Mapping
Glass Break
• Glass breaks, why?
– I held glass in air
– I release glass
– Gravity pulls on glass
– Glass hits floor and impact force
is higher than glass strength
• Changing any of the above factors
could have prevented the glass
break
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In cooperation with
Cause Mapping
Glass Break I was
thirsty
Glass was Glass held Waterglass
heavier due in air was nearby
to water
Glass hits Glass is Muscle
floor released twitch
Property Glass
Goal Breaks
Impacted
Gravity
pulls on
glass
Glass was Glass was
not impact made of
resistant reg. glass
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In cooperation with
Cause-Effect Mapping
Personal Observations
• A great tool to use for building a logical sequence of Cause-Effect
relationsships.
• Requires brainstorming sessions only to come up with individual sets of
Cause-Effect relationsships, a good combination with the thinking hats.
• Can be scaled up and down as neccessary depending on the size and
severity of the problem analysed.
• May require assistance from other tools such as timelines for verification
of Cause-Effect relationsships.
• Documentation can be deepened to show the consequences of a Cause-
Effect relationsship happening by placing the Cause-Effect mapping
relationsships onto a FMECA chart.
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