CAPA, Root Cause Analysis, and
By Joseph F. Tarsio, M.B.A., Ph.D.
March 17, 2015
What is CAPA?
Corrective and Preventative Action
(CAPA) is a system of quality procedures
required to eliminate the causes of an
existing nonconformity and to prevent
recurrence of nonconforming product,
processes, and other quality problems.
“Corrective and Preventive Action,” Quality System Regulation (QSR), 21
CFR Part 820, Medical Devices, Subpart J, Sec. 100, Became effective
on June 1, 1997, Replacing the 1978 GMP for Medical Devices.
“Overview of the Quality System Regulation for Medical Devices,”
Kimberly Trautman – Food and Drug Administration, USA and Chair,
Study Group 3, June 29, 1999.
“QSIT Corrective & Preventive Actions,” Quality System Inspection
Techniques (QSIT) Guide, August 1999.
“Establishment and Maintenance of a Quality Program.” Human Cells,
Tissues, And Cellular And Tissue-Based Products (HCT/P's), 21 CFR
Part 1271 Subpart D, Current Good Tissue Practice (cGTP), Sec. 160,
May 25, 2004. Revised as of April 1, 2006,
Nonconforming Material or Process (Discrepancy) - Any
material or process that does not meet its required specifications
or documented procedure.
Correction – Refers to repair, rework, or adjustment and relates
to the disposition of an existing nonconformity.
Corrective Action - To identify and eliminate the causes of
existing nonconforming product and other quality problems.
Preventive Action - To identify and eliminate the causes of
potential nonconforming product and other quality problems.
2. Move items
Nonconformance Control Steps
Components Of Corrective Action
Collect and analyze data to identify nonconforming
product, incidents, concerns or other quality
problems that would be worth the effort to correct
Investigate and identify root cause
Implement the correct solution
Verify or validate effectiveness
1. Would the
4. See if it
Corrective Action (CA) Steps
Ascertaining Root Cause
Root cause and the “weed”:
Weeds can be difficult to remove once they
start to grow and spread.
On the surface, the weed is easy to see.
However, the underlying cause of the weed, its root,
lies below the surface and is not so obvious.
To eradicate the weed you have to get below the
surface, identify the root, and pluck it out.
Thus, you have to go beyond the obvious, ascertain an
accurate route cause, so the appropriate corrective
action can be pursued to prevent recurrence.
Tools for Ascertaining Root Cause
Include the following:
The five whys, a simplistic approach exhausting the
Fishbone diagram, a cause and effect diagram also
known as the Ishikawa diagram.
Pareto analysis, the 80/20 rule premised on a
predefined database of known problems.
Fault tree analysis, a quantitative diagram used to
identify possible system failures.
Failure modes and effects analysis (FMEA), which lists
all potential failure modes and the potential
consequences associated with each failure mode.
The Five Whys Technique
The 5 Whys technique is a simpler form of fault tree
analysis for investigations, especially investigations of
specific accidents as opposed to chronic problems.
The 5 Whys technique is a brainstorming technique
that identifies root causes of accidents by asking why
events occurred or conditions existed.
The 5 Whys process involves selecting one event
associated with an accident and asking why this event
occurred. This produces the most direct cause of the
Drill down further indicating if their were any sub-
causes of the event, and ask why they occurred.
Repeat the process for the other events associated with
Disadvantages of the 5 Whys Technique
This time consuming brainstorming process may be
tedious for team members trying to reach consensus.
This is especially true for large teams.
Results are not reproducible or consistent. Another
team analyzing the same issue may reach a different
solution. The particular brainstorming process that
was utilized may be difficult, if not impossible, to
Root causes may not be identified. The 5 Whys
technique does not provide a means to ensure that root
causes have been identified.
Creating a Fishbone Diagram – Initial Steps
A fishbone diagram is a cause and effect diagram that
looks much like a skeleton of a fish.
It is also called a Ishikawa diagram after the inventor
of the tool, Kaoru Ishikawa who first used the
technique in the 1960s.
To draw the diagram, first list the problem/issue to be
studied in the head of the fish.
Label each bone of the fish. The major categories
typically used are: The 6 M’s: Machines, Methods,
Materials, Measurements, Mother Nature
(Environment), Manpower (People).
Repeat this procedure with each factor under the
category to produce sub-factors.
Continue asking, “Why is this happening?” and put
additional segments under each sub-factor.
Simple Fishbone Diagram
Bioburden Levels Out of Specifications
Creating a Fishbone Diagram – Further Steps
Continue adding sub-factors to your diagram
until you no longer get useful information as you
ask, “Why is that happening?”
Analyze the results of the fishbone after team
members agree that an adequate amount of detail
has been provided under each major category. Do
this by looking for those items that appear in
more than one category. These become the ‘most
For those items identified as the “most likely
causes”, the team should reach consensus on
listing those items in priority order with the first
item being the most probable” cause.
Simple Fishbone Diagram
Patient Received Incorrect Dose of Medication
needs not met
needs not met
Very Detailed Fishbone Diagram
Increased Outpatient Department Waiting Time
Advantages of Fishbone Diagrams
Fishbone diagrams do provide value in that they:
(1) organize potential causes,
(2) help a team to think through causes they might
otherwise miss, and
(3) provide a living document that shows the
status of all potential causes and whether they
have been proved/disproved/acted upon.
Limitations of Fishbone Diagrams
One danger with fishbone diagrams is that they
create a divergent approach to problem solving,
where the team expends a great deal of energy
speculating about potential causes, many of
which have no significant effect on the problem.
This approach may leave a team feeling
frustrated and hopeless.
Therefore in deciding which problems to explore
the team needs to closely look at the evidence in
order to separate fact from opinion.
The Pareto chart is a bar graph whose invention is
attributed to the Italy economist, Mr. Vilfredo Pareto.
In 1906, Vilfredo Pareto made the well-known
observation that 20% of the population owned 80%
of the property in Italy.
This was later generalized by Joseph M. Juran and
others into the so-called Pareto principle – that for
many phenomena, 80% of consequences stem from
20% of the causes.
In the Pareto chart, the lengths of the bars represent
frequency or cost (time or money), and are arranged
with longest bars on the left and the shortest to the
right. In this way the chart visually depicts which
situations are more significant (a Pareto analysis).
Pareto Frequency Chart
Shipping Documents Complaints
Results: This Pareto Chart shows that approx. 70% of the document complaints reported
involve quality certificates.
Significance: More care should be given to how quality certificates are written and added
to the shipping package.
When to Use a Pareto Chart
When analyzing data about the frequency of
problems or causes in a process.
When there are many problems or causes and
you want to focus on the most significant.
When analyzing broad causes by looking at
their specific components.
When communicating with others about your
Advantages of Pareto Charts
The main advantages of Pareto charts are
that they are easy to understand as well as
Many managers prefer to see an analysis
that is easy to represent and understand
and a Pareto chart is strong tool for that.
Disadvantages of Pareto Charts
Focusing on the Pareto chart alone may lead to the
exclusion from further consideration of minor
sources driving defects and non-conformances.
Another disadvantage of generating Pareto charts
is that they cannot be used to calculate the average
of the data, its variability or changes in the
measured attribute over time. Without quantitative
data it isn't possible to mathematically test the
values or to determine whether or not a process
can stay within a specification limit.
Fault Tree Analysis (FTA)
Fault tree analysis was first introduced by Bell
Laboratories and is one of the most widely used
methods in system reliability, maintainability and safety
It is a deductive procedure used to determine the various
combinations of hardware and software failures and
human errors that could cause undesired events
(referred to as top events) at the system level.
The deductive analysis begins with a general conclusion,
then attempts to determine the specific causes of the
conclusion by constructing a logic diagram called a fault
tree. This is also known as taking a top-down approach.
Fault Tree Analysis (continued)
The main purpose of the fault tree analysis is to
help identify potential causes of system failures
before the failures actually occur.
It can also be used to evaluate the probability of
the top event using analytical or statistical
After completing an FTA, you can focus your
efforts on improving system safety and reliability.
To do a comprehensive FTA, follow these steps:
1.Define the fault condition, and write down the top level
2.Using technical information and professional judgments,
determine the possible reasons for the failure to occur.
These are level two elements because they fall just
below the top level failure in the tree.
3.Continue to break down each element with additional
gates to lower levels. Consider the relationships between
the elements to help you decide whether to use an "and"
or an "or" logic gate.
4.Finalize and review the complete diagram. The chain can
only be terminated in a basic fault: human, hardware or
5. If possible, evaluate the probability of occurrence for
each of the lowest level elements and calculate the
A Simple Fault Tree Analysis
And gate - represents a condition in
which all the events shown below the
gate (input gate) must be present for the
event shown above the gate (output
event) to occur. This means the output
event will occur only if all of the input
events exist simultaneously.
Or gate - represents a situation in which
any of the events shown below the gate
(input gate) will lead to the event shown
above the gate (output event). The event
will occur if only one or any
combination of the input events exists.
Advantages of Fault Tree Analysis
FTA focuses on the judgment of experts from
varied disciplines and provides a common
language and perspective for the problem.
Both agreements and differences in opinion on
the inputs and importance are accounted for in
Members are not likely to feel threatened, due to
the focus on how the system operates, not
Graphic description clearly communicates the
possible causes of failure.
Disadvantages of Fault Tree Analysis
FTA relies on several expert opinions and
judgments at several stages. This makes it
very prone to inaccuracy.
In large systems, computer algorithms are
needed to accomplish the quantitative
Failure Modes and Effects Analysis (FMEA)
Begun in the 1940s by the United States military, FMEA
was further developed by the aerospace and automotive
FMEA is a step-by-step approach for identifying all
- in a design (“design FMEA”),
- in a manufacturing or assembly process (“process
- or in a final product or service (“use FMEA”).
“Failures” are any errors or defects, especially ones that
affect the customer, and can be potential or actual.
“Failure modes” means the ways, or modes, in which
something might fail.
“Effects analysis” refers to studying the consequences, or
effects, of those failures.
Analyzing Failure Effects through FMEA
Failure can be represented by a Risk Priority Number
Risk Priority Numbers (RPN’s), can be ranked according
to the following:
RPN = (Potential Severity) x (Likelihood of Occurrence)
x (Ability to Detect).
For all numerical weights, a common industry standard
is to us a 1 to 5 scale. For likelihood of occurrence for
example use 1 to represent “practically impossible” and
5 to indicate “occurs frequently.”
When applying FMEA, the high-priority failures—
identified by higher RPN’s—are examined first. For the
failure, a root cause is identified and a corrective action
is developed to eliminate the root cause .
Corrective Action for High Ranking Failures
Recommended action(s) to address potential failures
that have a high RPN could include for example:
-specific inspection, testing or quality procedures;
-selection of different components or materials;
-limiting the operating range or environmental
-redesign of the item to avoid the failure mode;
-performing preventative maintenance;
-inclusion of back-up systems or redundancy.
Assign responsibility and a target completion date for
the above actions. This makes responsibility clear-cut
and facilitates tracking.
Follow Up on Corrective Actions for High RFP
Indicate the action(s) taken for each high ranking
failure (those having a high RPN).
After those actions have been taken, re-assign a
new RPN based on the likelihood for the failure to
occur again, and to what severity, and also as to
how easy or harder it would be to detect again.
Determine with the new RPNs to what extent the
failures are now under control. Are any further
Update the FMEA as to how the design, process,
or final product/service has been improved.
Advantages of FMEA
Stimulates open communication of potential failures
and their outcomes.
Requires that all known or suspected potential
failures be considered.
Ranks failures according to risk.
Results in actions to reduce failure.
Results in actions to reduce risk.
Includes a follow up system and re-evaluation of
potential failures that favors continual improvement.
Limitations of FMEA
FMEA may not be able to discover complex
failure modes involving multiple failures or
Without follow up sessions, the process will not
Follow up RPNs may be less instructive
regarding improvement from severe failure since
detection and occurrence can always be reduced
but it is only in rare cases that severity ratings
can be reduced.
Preventive Action and Risk Management
It involves the gathering of precursor data & the
analysis of their risk.
Risk is a combination of likelihood of those or
similar events happening at your site, how easy
they are to detect, and what would be the
consequences (as can be seen in the RPNs for
Preventive Action and Risk Management (continued)
Determine your risk tolerance (also called risk appetite)
Apply resources to lower unacceptable risks through
accept – if the risk is acceptable let it go & reevaluate
transfer – if the risk is unacceptable, the risk should
perhaps be transferred to an insurance carrier
mitigate – use change management principles to mitigate
reoccurrence (the preventive action).
Refresh your data by adjusting the risk profile achieved
after ATM and whether the risks are now within your risk
1. Gather and analyze
2. Determine risk tolerance.
Compare the risk you are
facing versus your risk
3. Accept risk, transfer
risk, or decrease risk
4. Follow-up on the
of the actions taken.
Preventive Action and Risk Management (continued)
Communications Component Of Corrective And
Preventive Action (CAPA)
Communicate information about quality problems,
changes made, outcomes, and trends to those persons
directly responsible and to the staff in general
Forward information for management review
Work with staff and management to produce continuous
CAPA Case Studies
Weak CA, Weak PA (Common)
Weak CA, Strong PA (Unusual)
Strong CA, Weak or Unlinked PA (Common)
Strong PA Linked to a Strong CA (Ideal)
Case Study No. 1
The company develops biopharmaceuticals
The company has a CAPA program
A review of existing internal and external audits
• nonconformities are documented
• corrections are proposed (a temporary or permanent
change, repair, rework, or scrap)
• corrections made are timely
• but the same nonconformities seem to reoccur over and
• customers are complaining
The current investigation indicates that:
• nonconformities are not adequately categorized and
• the root causes of existing nonconformities are not
adequately investigated or addressed
• preventive actions are not sufficient to eliminate the
reoccurrence of the nonconformity
• discrepancy and CAPA procedures are not well-written
or difficult to follow
• the forms utilized don’t follow the flow of the procedure
• the forms do not provide enough space for more than a
• verbal decisions are not written down
• responsible people are assigned but a timelines for the
follow-ups is not given or is vague
Revise all Quality Assurance Procedures to
emphasize CAPA and to link discrepancy reporting
and disposition to preventive action
Initiate a trending and root cause analysis program
Present these programs to management and to the
Revise the nonconformity, CA, and PA forms
Conduct formal CAPA training
Reinforce CAPA awareness in verbal
Provide a “Quality Update” at the company’s monthly
Easier to follow quality procedures
More user-friendly forms
A better understanding of processes obtained
through root cause analysis
More proactive thinking vs. reactive thinking
Less scrap and rework
Fewer customer complaints
Number of Nonconformities
1 2 3