Failure Modes and Effects Analysis (F.M.E.A)

Failure Modes and Effects Analysis - A Hazard Identification Technique

Introduction

Failure is a state or condition of the system, process, procedure, or equipment of not meeting the desired target or condition. In other words, it is the termination of the equipment, process, or worker's ability to perform the desired action. Failure Modes and Effects Analysis (F.M.E.A) is a technique used to identify the modes of the failure of the process, or equipment and the critical effects it has on the system so that they can be analyzed.

The technique consists of two different phases which are described as "Failure Mode" which refers to the means or ways in which a product, equipment, or process can fail. "Effects Analysis" is the stage that includes the decomposition of these failures into sub-components and parts for the detailed examination. In summation, Failure Mode and Effects Analysis (F.M.E.A) refers to a step-by-step approach to systematic inspection of components of a system, product, or process, and identifying the critical effects on the end user so that improvements can be suggested by providing proffering cost-effective solutions.

It is also used in incident investigation, and hazard identification as well as during the designing of the equipment so that the equipment that can fail can be identified and suitable action is taken to prevent the mishap. The findings are documented and made available to all of the involved stakeholders. In the continuous process, it is like a living document with credible information about the equipment that can fail at any time and how to control the accident.

What is the Importance of Failure Modes and Effects Analysis technique?

• Presents options for addressing the failure modes and their consequences in advance;
• Comprehensive fault detection mechanism;
• Assists in assessing the performance of the system;
• An effective mechanism for identifying the critical impact on human safety during system failure;
• Provides an opportunity to adapt cost-effective controls against identified failure modes;
• Product and process reliability is enhanced;
• Provides an opportunity to satisfy the customer;

When to Perform Failure Modes and Effects Analysis?

The Failure Modes and Effects Analysis technique is used in various circumstances but generally, it is ideal for use when;

• When a product, process, or equipment is being designed or redesigned;
• When an existing equipment, product, or process is being applied in a different manner;
• When modifying the existing controls and suggesting new plans;
• When a customer is not satisfied as indicated by the feedback;
• When the existing system or product is being analyzed for failure
• Hazard Identification, Incident Investigation;
• On regular intervals throughout the life of the product, process, equipment, etc.;

Types of Failure Modes and Effects Analysis (F.M.E.A)

There are two major types of the FMEA technique;

• Design Failure Modes and Effects Analysis (DFMEA)

This deals with product failure possibility and the consequent impact on safety and the environment. The design stage is analyzed for components failure by considering the factors like material properties, noise, components interaction, geometry, etc.

• Process Failure Modes and Effects Analysis (PFMEA)

This address the process failure possibility with consequent impact on process reliability, customer satisfaction level, and safety hazards. Factors like manufacturing procedure, operational procedure, environment, human behavior, etc., are considered.

Procedure for Implementing Failure Modes and Effects Analysis (F.M.E.A)

A general procedure is mentioned hereunder which can be taken as a guideline and can be tailored as per the industry since the FMEA procedure is different for industry and activity.

Assemble a cross-functional team involved in the development of the product/ process with diverse knowledge of components, process, operating procedure, customer needs, etc. These functions can include designing, manufacturing, reliability, quality, maintenance, procurement, sales and customer service, etc.

• Product/ Process Description

Understand the process of the product being considered for the FMEA process. What can go wrong and in what manner so that credible control is implemented?

• Flow Chart Creation

Develop a block flow chart to show the relationship between the components of a system or process steps and how it works?

• Function Identification

The product or Process function is identified clearly and questions about it are asked properly.

• Failure Modes

All failure modes in which equipment or components can fail to meet the desired target are identified.

• Consequences Identified

What are effects on the overall system, environment, human safety, behavior, etc are identified? What happens when the system fails? Process engineers should be consulted during this phase to collect comprehensive information.

• The severity of Failure Determination

The severity rating is allocated between 1 to 10 where 1 is insignificant and 10 is catastrophic. This helps in prioritizing the issues and catastrophic one is dealt with on a priority basis.

• Root Cause Identification

The root cause of each failure mode is determined and recorded. It can be either a weakness in the design phase or a shortcoming in an operating procedure. All of the root causes should be recorded and documented.

• Occurrence Likelihood

This includes the likelihood of failure of equipment/process during the lifetime, rated between 1 to 10 where 1 represents highly unlikely and 10 shows the failure will definitely occur.

• Control Measures Determination

The suitable controls should be identified and recorded for implementation to prevent the failure from reaching the user. These controls should prevent the occurrence or reduce the impact severity.

• Determination of Detection Rating

The control implemented should be determined how effective they are in tracing the failure mode or cause of failure before the user is affected. The rating is given between 1 to 10 where 1 shows the control will definitely detect the failure and 10 shows the control will not be able to detect the failure.

• Risk Priority Number (RPN)

Risk Priority Number (RPN) is representative of Severity, Occurrence, and Detection. This helps the process engineer to allocate the number to the failures and put them in an order according to their number so that the most severe can be addressed first.

• Identification of Recommended Actions

This includes the design or process changes to reduce the risk level or likelihood of occurrence.

• Responsibilities and Time Frame

Responsibilities should be allocated and the timeframe given to complete the task. It will provide the opportunity to track the progress of improvement.

• Results Determination

All of the results should be determined post-application of the suggested controls.

• Re-Assessment

Re-assessment should be conducted and a Risk Priority Number should be noted to ensure effectiveness.