FMEA: A Good Way to Save Yourself Some Grief
In the past couple of years, I've noticed a new acronym popping up across the Web. In case you've not yet encountered it, "FML" typically appears in social media updates about something gone awry. As in, "The cat ate my homework. FML!" Or, "My production line just broke down, and now the company is going to be short on a major order. FML!"
This acronym reminds me of an abbreviation used in Lean Six Sigma and quality improvement: FMEA. It's short for "Failure Modes and Effects Analysis," which basically means "look very, very carefully at how and why stuff can go wrong."
FMEA: Failure Modes and Effects Analysis
In the context of a quality project, you'd use an FMEA to systematically:
- Identify different ways a product or process might break down
- Note the effects that could result from these failures
- Figure out the potential causes of these failures and the risk associated with each
- List and rank actions you can take to reduce the risk of failure
I wonder how many of these laments could be prevented by a good FMEA?
How to Do an FMEA
The FMEA process typically includes the following:
- Identify potential failure modes for each step/input in your process.
- Determine the failure effects associated with those failure modes.
- Identify possible causes for each failure mode.
- List any controls that are in place to prevent these causes happening.
- Assign a numerical value to the Severity of the effect, the likelihood of Occurrence, and the chance of Detecting the failure mode before it causes a defect.
- Multiply the the values for severity, occurrence, and detection to get a risk priority number (RPN).
- Improve any items with a high RPN. Record the actions you've taken, and then revise the RPN.
- Maintain as a living document.
You can use just a pencil and paper to do an FMEA, although Minitab's Companion process improvement software has a built-in FMEA form that shares data with process maps and other forms you'll need for your project, making it easy to complete:
When you've completed the FMEA, you'll have the answers to these questions:
- What are the potential failure modes at each step of a process?
- What is the potential effect of each failure mode on the process output, and how severe is it?
- What are the potential causes of each failure mode, and how often do they occur?
- How well can you detect a cause before it creates a failure mode and effect?
- How can you assign a risk value to a process step, that factors in the frequency of the cause, the severity of failure, and the capability of detecting it in advance?
- What part of the process should an improvement project focus on?
- Which inputs are vital to the process, and which aren't?
- How can reaction plans be documented as part of process control?
When Can You Use the Results of the FMEA?
The FMEA is a great tool to use early on in a quality improvement project, because it collects and organize data about a process that can help you identify and scope a process improvement project. It's also good for identifying and screening potential vital X's as you complete a project. And at the end of a project, you can use the FMEA to document status, reference reaction plans, and note any further improvements the process may require over time.
Where could doing an FMEA help you?