Root Cause Analysis
Tracing a
Problem to its Origins
In medicine, it's easy to
understand the difference between treating the symptoms and curing the
condition. A broken wrist, for example, really hurts! But painkillers will only
take away the symptoms; you'll need a different treatment to help your bones
heal properly.
But what do you do when you have
a problem at work? Do you jump straight in and treat the symptoms, or do you
stop to consider whether there's actually a deeper problem that needs your
attention? If you only fix the symptoms – what you see on the surface – the
problem will almost certainly return, and need fixing over, and over again.
However, if you look deeper to
figure out what's causing the problem, you can fix the underlying systems and
processes so that it goes away for good.
Root Cause Analysis (RCA) is a
popular and often-used technique that helps people answer the question of why
the problem occurred in the first place. It seeks to identify the origin of a
problem using a specific set of steps, with associated tools, to find the
primary cause of the problem, so that you can:
- Determine
what happened.
- Determine
why it happened.
- Figure
out what to do to reduce the likelihood that it will happen again.
RCA assumes that systems and
events are interrelated. An action in one area triggers an action in another,
and another, and so on. By tracing back these actions, you can discover where
the problem started and how it grew into the symptom you're now facing.
You'll usually find three basic types of causes:
- Physical causes – Tangible, material
items failed in some way (for example, a car's brakes stopped working).
- Human causes – People did something
wrong, or did not do something that was needed. Human causes typically
lead to physical causes (for example, no one filled the brake fluid, which
led to the brakes failing).
- Organizational causes – A system,
process, or policy that people use to make decisions or do their work is
faulty (for example, no one person was responsible for vehicle
maintenance, and everyone assumed someone else had filled the brake
fluid).
RCA looks at all three types of
causes. It involves investigating the patterns of negative effects, finding
hidden flaws in the system, and discovering specific actions that contributed
to the problem. This often means that RCA reveals more than one root cause.
You can apply RCA to almost any
situation. Determining how far to go in your investigation requires good
judgment and common sense. Theoretically, you could continue to trace root
causes back to the Stone Age, but the effort would serve no useful purpose. Be
careful to understand when you've found a significant cause that can, in fact,
be changed.
The Root Cause Analysis Process
RCA has five identifiable steps.
Step 1 :
Define the Problem
- What happening?
- What
are the specific symptoms?
Step 2 :
Collect Data
- What
proof do you have that the problem exists?
- How
long has the problem existed?
- What
is the impact of the problem?
You need to analyze a situation
fully before you can move on to look at factors that contributed to the
problem. To maximize the effectiveness of your RCA, get together everyone –
experts and front line staff – who understands the situation. People who are
most familiar with the problem can help lead you to a better understanding of
the issues.
A helpful tool at this stage
is CATWOE .
With this process, you look at the same situation from different perspectives:
the Customers, the people (Actors) who implement the solutions, the
Transformation process that's affected, the World view, the process Owner, and
Environmental constraints.
Step 3 : Identify Possible Causal Factors
- What sequence of events leads to the problem?
- What conditions allow the problem to occur?
- What other problems surround the occurrence of the
central problem?
During this stage, identify as
many causal factors as possible. Too often, people identify one or two factors
and then stop, but that's not sufficient. With RCA, you don't want to simply
treat the most obvious causes – you want to dig deeper.
Use these tools to help identify
causal factors:
- Appreciation –
Use the facts and ask "So what?" to determine all the possible
consequences of a fact.
- 5 Whys –
Ask "Why?" until you get to the root of the problem.
- Drill Down –
Break down a problem into small, detailed parts to better understand the
big picture.
- Cause and Effect Diagrams –
Create a chart of all of the possible causal factors, to see where the
trouble may have begun.
Step 4 : Identify the Root Cause(s)
- Why does the causal factor exist?
- What is the real reason the problem occurred?
Use the same tools you used to
identify the causal factors (in Step Three) to look at the roots of each
factor. These tools are designed to encourage you to dig deeper at each level
of cause and effect.
Step 5 : Recommend and
Implement Solutions
- What can you do to prevent the problem from happening
again?
- How will the solution be implemented?
- Who will be responsible for it?
- What are the risks of implementing the solution?
Analyze your cause-and-effect
process, and identify the changes needed for various systems. It's also
important that you plan ahead to predict the effects of your solution. This
way, you can spot potential failures before they happen.
One way of doing this is to
use
Failure Mode and Effects Analysis (FMEA).
This tool builds on the idea of risk analysis to identify points where a
solution could fail. FMEA is also a great system to implement across your
organization; the more systems and processes that use FMEA at the start, the
less likely you are to have problems that need RCA in the future.
Impact Analysis is
another useful tool here. This helps you explore possible positive and negative
consequences of a change on different parts of a system or organization.
Another great strategy to adopt
is
Kaizen , or
continuous improvement. This is the idea that continual small changes create
better systems overall. Kaizen also emphasizes that the people closest to a
process should identify places for improvement. Again, with Kaizen alive and
well in your company, the root causes of problems can be identified and
resolved quickly and effectively.
Key Points
Root Cause Analysis is a useful
process for understanding and solving a problem.
Figure out what negative events
are occurring. Then, look at the complex systems around those problems, and
identify key points of failure. Finally, determine solutions to address those
key points, or root causes.
As an analytical tool, RCA is an
essential way to perform a comprehensive, system-wide review of significant
problems as well as the events and factors leading to them.
Root Cause Analysis
Root cause analysis is an approach for identifying the
underlying causes of why an incident occurred so that the most effective
solutions can be identified and implemented. It's typically used when
something goes badly, but can also be used when something goes well.
Within an organization, problem solving, incident investigation and root cause
analysis are all fundamentally connected by three basic questions: What's
the problem? Why did it happen? and What will be done to prevent it?
The Cause Mapping method of Root Cause Analysis
In the Cause Mapping method, the word root,
in root cause analysis refers to the causes that are beneath the surface.
Most organizations mistakenly use the term "root cause" to identify
the one, main cause. Focusing on a single cause can limit the solutions
set resulting in better solutions being missed. A Cause Map provides a simple
visual explanation of all the causes that were required to
produce the incident. Theroot is the system of
causes that reveals all of the different options for solutions.
There are three basic steps to the Cause Mapping method:
- Define
the issue by its impact to overall goals
- Analyze
the causes in a visual map
- Prevent
or mitigate any negative impact to the goals by selecting the most
effective solutions.
What is a Cause Map?
A Cause Map provides a visual explanation of why an incident
occurred. It connects individual cause-and-effect
relationships to reveal the system of causes within an
issue. A Cause Map can be very basic and it can be
extremely detailed depending on the issue.
How to read a Cause Map
Start on the left. Read to the
right saying "was caused by" in place of the
arrows. Investigating a problem begins with the problem
and then backs into the causes by asking Why questions.
The questions begin, "Why did this effect happen?" The response
to this question provides a cause (or causes), which is written down to the
right.
The next question is again, "Why did this effect happen?" The cause
that was written down last becomes the effect for the next Why question. Anyone
who's ever had a three-year-old in their life will immediately recognize how
Why questions change a cause into an effect. This is fundamentally how causes
and effects link together to create a chain of events. Writing down 5-Whys,
shown below, is a great way to start an investigation because it's so simple.
In the Cause Mapping method, a problem within an organization is defined by
the deviation from the ideal state. A Cause Map always begins with
this deviation which is captured as the impact to the organizations
overall goals.
In addition to the standard Why questions, which tend to create linear
cause-and-effect relationships, the Cause Mapping method also asks "What
was required to produce this effect?" Anything that is required to produce
an effect is a cause of that effect. This question, "What was
required?," builds a detailed Cause Map that provides a more complete
representation of the actual issue.
Why does the Cause Map read Left to Right?
It should be noted that the
popular fishbone cause-and-effect diagram starts with the problem on the right
and builds the causes to the left. It was created by Kaoru Ishikawa (1915-1989)
in Japan. The fishbone diagram builds from right to left because the Japanese
language reads from right to left. The Cause Mapping method actually uses
Ishikawa's convention by asking Why questions in the direction we read.
The fishbone is widely recognized as one of the standard quality tools.
Ishikawa was a pioneer with his approach. The fishbone cause-and-effect
diagram is part of every six-sigma program. A Cause Map builds
on the original lessons with the fishbone with some subtle, but important
distinctions. A fishbone starts with just one, single problem
which doesn't reflect the nature of real world issues. It
reads right to left because the Japanese language
reads that direction. It mixes causes and possible causes without
specifying evidence. And, it breaks apart the fundamental
cause-and-effect relationships within an issue by grouping the causes
into general categories.
5-Whys on a Cause Map
The 5-Why approach is an
excellent example of basic cause-and-effect analysis. Just as a journey of a
thousand miles begins with the first step; every investigation, regardless of
size, begins with one Why question. The Why questions then continue, passing through
five, until enough Why questions have been asked (and answered) to sufficiently
explain the incident. The 5-Why approach, created by Sakichi Toyoda (1867 -
1930), the founder of Toyota, is a simple way to begin any investigation. A
Cause Map can start with just 1-Why and then expand to accommodate as many Why
questions as necessary. Some refer to the Cause Mapping method as "5-Whys
on Steroids."
Problems within an organization are typically not singular. In the real
world, a problem typically impacts more than one goal. The Cause Map
starts with the impact to the goals even if more than one goal is
impacted. If the causes are all part of one incident then the causes and
the goals will all be connected on one Cause Map.
Some causes are linked with AND In between
ANDs show where more than one
cause is required. When an effect has more than one cause, both causes are
placed on the Cause Map. Each cause is connected to the effect with an AND
placed inbetween. These causes are independent of each other, but they are both
required to produce that effect. An AND is needed when people provide
different, yet valid, explanations of a cause. People think of cause-and-effect
as a simple one-to-one relationship; an effect has a cause. In reality, every
effect has causes.
