What Is Root Cause
Failure Analysis?
Root Cause Failure Analysis or RCFA as it is
sometimes called, tends to have a different meaning depending upon who you ask.
To put it simply, it is a method or series of actions taken to find out why a
particular failure or problem exists and correcting those causes. It is similar
to what detectives do when a crime occurs or what the NTSB does when an
airplane crashes.
Let’s talk a little about why you would want to conduct a Root Cause Failure
Analysis in the first place. It is a proven fact that most of the
failures/problems that plague industry are what we would call CHRONIC. This
means that they happen more than once for the same reason. Furthermore, out of
all of the CHRONIC failures that you experience in a given year, 20% of those
failures represent 80% of the loss. These are important facts to understand
when you think about the benefits of Root Cause Failure Analysis. It means that
if you investigate the 20% of the failures representing 80% of your losses, you
will reap quantum benefits in a short period of time. We call these few
failures the "Significant Few" failures.
Once we have identified the "Significant Few" failures, we must begin
analyzing. While there are many ways to go about this, I would like to talk
about a process that has been successfully field tested over a 30 year period.
This process is called PROACT™. PROACT™ is an acronym for the following:
PReserving
Failure Data
Ordering the Analysis
Analyzing the Data
Communicating Findings &
Recommendations
Tracking for Success
Let’s take a look at each of these steps in greater detail:
Preserving Failure Data
With any failure or problem it is of the utmost importance to collect data with
respect to that problem. Consider what an NTSB investigator does right after an
airplane crash. They comb the area for data such as the data flight recorder
("black box"), broken airplane parts, instrument readings, etc. You
must do the same when you are analyzing a problem. We have a data collection
procedure called the 5P’s. The 5P’s are the categories of information necessary
to collect to begin analyzing a failure. The 5P’s stands for People, Parts,
Paper, Position and Paradigms. As an analyst, you must, through interviews,
brainstorm with all of the people involved to collect the other items based on
these 5 categories.
Ordering the Analysis
It would be difficult to analyze any problem by yourself and it would be
unrealistic to think you could analyze a "Significant" problem
without the assistance of a multi-disciplined group of individuals. Ordering
the analysis consists of putting the right expertise on your team. You need a
Principal Analyst to facilitate your Root Cause Failure Analysis project and a
team of analysis experts. In addition to this team of experts, you need to
delineate exactly what your team charter or objective is. This creates focus
for the team. The team must also delineate exactly what rule or guideline they
will follow while analyzing this problem. We call these critical success
factors or CSF’s for short.
Analyzing the Data
Once you
have assembled your team and have collected the critical data, you must now
begin to analyze the problem. PROACT™ uses a logic tree process to help the
team members focus on the problem at hand. They break the problem down to it
smallest components and then begin hypothesizing as to what the underlying
causes might be. The logic tree is broken down to 5 basic steps:
The team asks a series of "How Can" questions to come up with their
hypotheses. For instance, if our failure mode is a failed bearing our
hypotheses might be fatigue, overload, corrosion and erosion. We then have to
use real field data to prove or disprove the analysis team’s hypothesis. Once
all hypotheses have been proven or disproved we can assess which underlying
causes are physical, human or latent. These are the three main categories of
problem or failure causes. The logic tree is really a visual brainstorming tool
to help you logically figure out the root cause of a problem.
Communicate Findings and Recommendations to Decision Makers
Once you
have successfully completed the search for causes with your logic tree, it is
now time to communicate your findings and solutions to the decision-makers. You
must provide a detailed report to help the decision-makers understand the
effectiveness of your failure analysis so that your recommendations are given a
fair assessment. You must create such a compelling case that it would seem
foolish not to go ahead with your recommendations.
Tracking for Results
Assuming that your communication with the decision-makers was successful, you
must now track the effectiveness of your recommendations to make sure that you
are getting the return on investment that you have anticipated. You can do this
with a number of measurements such as reduced maintenance costs, improved production
rates, reduced failure rates, etc…
Companies
who successfully apply the PROACT™ methodology have captured returns in excess
of 800% to 1000%. These numbers may sound unrealistic, but think about what
failures cost the average company. Remember that these failures are chronic, so
if we do not eliminate them they WILL happen again.
Source of Aricle:
http://www.maintenanceresources.com/ReferenceLibrary/