Identify Problems Right Away! | Failure Mode and Effect Analysis (FMEA)
Likely you’ve experienced or read about product recalls or poorly designed products and processes. When these failures become public knowledge, manufacturers, service providers, and suppliers are deemed incapable of creating safe or reliable products, and the company’s reputation is negatively impacted. Failure Mode and Effect Analysis (FMEA) is a technique that helps businesses to anticipate failure early in the design phase by identifying all potential failure modes in a design or production process so that appropriate actions can be taken to mitigate risk and prevent failures.
The applications of FMEAs are almost limitless. Early applications were safety-oriented in the aerospace business. FMEA has since spread into manufacturing, design, administrative, software, accounting, and finance processes to help eliminate errors and reduce failures and customer complaints. Wherever we apply FMEA, the earlier it is used in the life cycle of a product or process, the greater the potential for positive results.
The Fundamentals of FMEA
FMEA is a quality planning tool to identify and eliminate potential product and process failures or defects. It is a proactive and systematic methodology, anticipating failures before they happen so that appropriate actions can be taken to reduce risk. FMEA aids in identifying failure modes, possible causes of the failure modes, and current controls to detect or prevent the failure modes/causes before escaping to the customer. FMEA is frequently documented in a spreadsheet (template), and a risk priority number (RPN) is calculated to help prioritize the highest risk areas.
FMEA is one of the best ways to find potential reliability problems early in development. This lets manufacturers act quickly and avoid failure. Early problem detection lets practitioners plan for possible problems and include strong, safe, and easy-to-use components. Potential losses are ranked by how severe their effects are, how likely the possible causes are, and how effective the current controls are for detecting or preventing the failure mode/cause from happening.
Types of FMEA
The most common types of FMEA are Process FMEA (PFMEA) and Design FMEA (DFMEA). In a process FMEA, each step of the process is carefully analyzed to determine the intended functions for those steps, the possible failure modes, the effect and severity of the failure if it happens, the possible causes and likelihood of those causes, as well as the current controls and effectiveness of those controls. A design FMEA starts with the components/functions of a design and identifies failure modes, their effect and severity, possible causes, and the likelihood of those causes, along with the current controls.
No matter what type of FMEA is conducted, the intent is quite simple: identify what could go wrong along with possible reasons, so that appropriate action(s) can be taken to reduce risk and eliminate or minimize the chance of escaping failures or defects.
Preparing for an FMEA
Some important things to address before beginning an FMEA include:
- Form an appropriate team (preferably cross-functional) and select a team leader. All team members must know who the FMEA owner is.
- Thoroughly define the process, product, or defect studied. For a process FMEA, this is best accomplished with a process flow diagram. For a design FMEA, a blueprint, prototype, or system diagram with a function map is helpful.
- Clearly define the FMEA boundaries. What steps, systems, sub-systems, components, etc. will be included?
Steps for Conducting an FMEA
A template (spreadsheet) is often used when conducting and documenting an FMEA. The general steps for FMEA are:
- Study the process/product to be analyzed
- Brainstorm the possible failure modes
- List the potential consequences (effects) of each failure mode
- Assign severity (SEV) scores to each consequence
- Identify the possible cause(s) of each failure mode
- Assign occurrence (OCC) scores for each cause
- Identify current controls to detect the failure modes. What is being used to detect or prevent the cause of the associated failure mode?
- Assign an escaped detection (DET) score for each cause/control
- Calculate the Risk Priority Number (RPN) for each line in the FMEA by multiplying the severity, occurrence, and detection scores
- Prioritize the failure modes and causes based on RPN. The bigger the RPN, the greater the risk.
- Determine appropriate action(s) to be taken. How can we reduce the severity, occurrence, and escape detection scores?
- Recalculate the RPNs based on the action plans.
When should you use an FMEA?
Here are just a few situations where applying FMEA is effective:
- A product design is new, or there is an improvement (re-design) planned
- A service process is being designed or changed
- Adjustments, changes, and alterations are being made to the supply chain or a process
- You are making new control plans or revising old ones
- You are looking into the problems with how things, goods, or services are done now
FMEA Planning and Supporting Tools
The FMEA can be accomplished with several supporting tools and methods.
The list below isn’t a complete list of all the tools you can use but a good example of a few:
- Brainstorming
- Process Flow Diagram
- Block Diagram; System Diagram
- QbD Planning Worksheets
- Control Chart
- Benchmarking
- Graphical Analysis
- Statistical Analysis
- Cause-Effect Diagram
- Design of Experiments
- Regression/Correlation
- Fault Tree Diagram
- Cost/Benefit Studies
- Value Analysis
- Product/Process Design Matrix
Implementation of FMEA
One of the most important factors for implementing FMEA is timeliness. It is meant to be a “before-the-event” action. However, that does not mean we cannot still gain valuable information by applying an FMEA after the fact. However, the FMEA should be done to achieve the greatest value before a design or process failure mode is unknowingly designed into the product or process. Time spent up front doing a comprehensive FMEA correctly, when product/process changes can be most easily implemented, will alleviate late crises.
Get Started
Complex products and systems can be difficult to manage and even more difficult to keep from failing. A single failure can cause extensive damage, costing time, money, and resources. FMEA is proactive rather than reactive. The goal is to identify and prevent losses in the first place instead of waiting for them to happen and then trying to solve the problem.
Air Academy Associates includes FMEA as part of its Lean Six Sigma and Design for Six Sigma curriculum. Our experienced professionals can also work with you to create a plan to mitigate risks and keep your products and processes running smoothly.
