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. 

\s