(56a) Use of FEMA to Prioritize PS Incident Reduction Measures

Use of FEMA to Prioritize PS Incident Reduction Measures

By Florine Vincik BS, MBA, CSP, CPSP

September, 2015

FOREWARD

BASF initiated a Call to
Action to reduce Process Safety Incidents in 2014 to reduce the rate per
million man hours from 2.1 to 0.5 by the year 2025.  Process safety sites identified by rate and
number of PSI were identified and resources from the PS CoE group to assist
with tools and resources where needed. 
One site used in this study was familiar with the use of the failure
modes and effects analysis and was a willing pilot site for its
application.  This report outlines the
study steps taken and the resulting prioritized list of actions.  The site was successful in using the FMEA
output to assign resources where the highest priority was indicated.

BACKGROUND

Begun in the 1940s by the
U.S. military, FMEA was further developed by the aerospace and automotive
industries. Several industries maintain formal FMEA standards.

Failure modes and effects
analysis (FEMA) also called: potential failure modes and effects analysis;
failure modes, effects and criticality analysis (FMECA) is a step-by-step
approach for identifying all possible failures in a design, a manufacturing or
assembly process, or a product or service. This paper postulates the use of
FMEA for process safety to enable prioritizing PSI reduction activities based
on risk to harming people and interruption of business.

 “Failure modes” means the ways, or modes, in
which something might fail. Failures are any errors or defects, especially ones
that can create harm or affect the customer, and can be potential or actual.
“Effects analysis” refers to studying the consequences of those failures.

Failures are prioritized
according to how serious their consequences are, how frequently they occur and
how easily they can be detected. The purpose of the FMEA is to take actions to
eliminate or reduce failures, starting with the highest-priority ones.

Failure modes and effects
analysis also documents current knowledge and actions about the risks of
failures, for use in continuous improvement and risk assessments. FMEA is used
during design to prevent failures. Later it’s used for control, before and
during ongoing operation of the process. Ideally, FMEA begins during the
earliest conceptual stages of design and continues throughout the life of the
product or service. 

What follows is an overview
and example. Before undertaking an FMEA process, learn more about standards and
specific methods in your organization and industry through other references and
training.  A trained facilitator in FMEA
should be used until a team is trained on the technique.

When to Use FMEA for
Process Safety

FMEA may be used in Process Safety
to prioritize design/redesign
activities based on known risks (multiple of likelihood and severity) or
unknown risk (what if this were to happen, what impact could this have
regarding process safety). Regarding an existing process, changes occur and FMEA may be used to evaluate a change to a
process such as chemical, processing technique, equipment, manning or machines.  Most certainly, FMEA use before developing control plans for a new or modified process
is recommended.  Reduction of incident trends and planning improvement goals
for a process, product or service is the ideal application of this technique by
a group of knowledgeable personnel.  Analyzing failures of an existing
process is fertile ground for this technique and is sometimes
recommended as a result of an incident investigation. Throughout the life of
the process, product or service, this technique may be applied periodically by
groups such as operations, maintenance, engineering, safety, management to reassess future resource priorities
that may be limited.

 The “Simple” FMEA Technique Adapted for Process Safety (Inclusive of
Customer Focus):

1.       Assemble a cross-functional team of people with
diverse knowledge about the process, product or service and customer needs.
Functions often included are: design, manufacturing, quality, testing,
reliability, maintenance, purchasing (and suppliers), sales, marketing (and
customers) and customer service.

2.      Identify
the scope of the FMEA. Is it for concept, system, design, process or service?
What are the boundaries? How detailed should we be? Use a flowchart Start using the Flowchart Template (Excel, 57 KB). to identify the scope (including what is not in scope) and
to make sure every team member understands it in detail. (From here on, we’ll
use the word “scope” to mean the system, design, process or service that is the
subject of your FMEA.) Post the flowchart up in a visible location as a
reminder.

3.      Fill
in the identifying information at the top of your FMEA form. Figure 1 shows a
typical format. The remaining steps ask for information that will go into the
columns of the form.

Figure 1 FMEA Example
(click image to enlarge)

4.      Identify
the functions of your scope. Ask, “What is the purpose of this system, design,
process or service? What do our customers expect it to do?” Name it with a verb
followed by a noun. Usually you will break the scope into separate subsystems,
items, parts, assemblies or process steps and identify the function of each.

5.      For
each function, identify (use post its followed by
controlled brainstorming) all the ways failure could happen. These are
potential failure modes. If necessary, go back and rewrite the function with
more detail to be sure the failure modes show a loss of that function.

6.      For
each failure mode, identify all the consequences on the system, related
systems, process, related processes, product, service, customer or regulations.
These are potential effects of failure. Ask, “What does the customer experience
because of this failure? What happens when this failure occurs?”

7.      Determine
how serious each effect is. This is the severity
rating, or S. Severity is usually rated on a scale from 1 to 10, where 1
is insignificant and 10 is catastrophic. If a failure mode has more than one
effect, write on the FMEA table only the highest severity rating for that
failure mode.

8.      For
each failure mode, determine all the potential root causes. Use tools classified
as cause
analysis tool, as well as the best knowledge and experience of
the team. List all possible causes for each failure mode on the FMEA form.

9.      For
each cause, determine the occurrence rating, or O.
This rating estimates the probability of failure occurring for that reason
during the lifetime of your scope. Occurrence is usually rated on a scale from
1 to 10, where 1 is extremely unlikely and 10 is inevitable. On the FMEA table,
list the occurrence rating for each cause.

10.    For
each cause, identify current process controls. These are tests, procedures or
mechanisms that you now have in place to keep failures from reaching the
customer. These controls might prevent the cause from happening, reduce the
likelihood that it will happen or detect failure after the cause has already
happened but before the customer is affected.

11.    For
each control, determine the detection rating, or D.
This rating estimates how well the controls can detect either the cause or its
failure mode after they have happened but before the customer is affected.
Detection is usually rated on a scale from 1 to 10, where 1 means the control
is absolutely certain to detect the problem and 10 means the control is certain
not to detect the problem (or no control exists). On the FMEA table, list the
detection rating for each cause.

12.    Is
this failure mode associated with a critical characteristic? (Critical
characteristics are measurements or indicators that reflect safety or
compliance with government regulations and need special controls.) If so, a
column labeled “Classification” receives a Y or N to
show whether special controls are needed. Usually, critical characteristics
have a severity of 9 or 10 and occurrence and
detection ratings above 3.

13.   
Calculate the risk priority number, or RPN, which equals S × O × D. Also
calculate Criticality by multiplying
severity by occurrence, S × O. These
numbers provide guidance for ranking
potential failures in the order they should be addressed.

14.    Identify
recommended actions. These actions may be design or process changes to lower
severity or occurrence. They may be additional controls to improve detection.
Also note who is responsible for the actions and target completion dates.

15.   
As
actions are completed, note results and the date on the FMEA form. Also, note
new S, O or D ratings and new RPNs. A new higher RPN priority item should then
be addressed by assignment of resources (Iterative Process)

A FMEA Example: 

A site was experiencing a number of process safety
releases due to overflows and overfills as well as leaks of process fluids to
containment.  These type of process
safety incidents were analyzed over the periods of 2014-Feb 2016 and a team of
operations, maintenance, EHS, ERP, Process safety personnel spent 3, 2 hour
meetings performing FMEA on the identified near root causes specifically
equipment reliability, design input/output. 

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