Design Failure Mode and Effect Analysis (DFMEA) is a systematic group of activities used to determine how to recognize and evaluate potential systems, products or process failures. DFMEA identifies the effects and outcomes of failures, actions that could eliminate or mitigate the failures and provides a historical written record of the work performed.
With such a broad definition, it sounds like DFMEA could be all things to all people. However, it is not the best tool for every challenge. Is it the best solution for you?
In essence, DFMEA analyzes what might go wrong, how bad the effect may be and how to prevent, mitigate or detect failure at the earliest possible moment so it might be corrected at the point of least cost impact. This makes it an ideal fit for any discipline where risk reduction and failure prevention are crucial, including:
- Business processes
- Service industries
- Regulated industries
The DFMEA Process
DFMEA drills into failure from several angles to best determine why the loss of the expected or intended function under stated conditions occurred. There are four areas of analysis:
- Failure Mode: The way in which a failure is observed
- Failure Effect: The immediate consequences of a failure on the operation, function or functionality
- Failure Cause: The underlying cause of the failure, or things which initiate process which leads to failure (i.e., a defect in design, system, process, quality or part application)
- Severity: The consequences of a failure mode, framed in worst case outcomes of degree of injury, property damage or harm that could ultimately occur
The results are then taken to an even more granular level with the determination of a Risk Priority Number (RPN), calculated based on:
- Severity of the failure effect (S): A value applied on a scale of 1 (low) to 10 (high)
- Frequency of failure occurrence (O): A value applied on a scale of 1 (infrequent) to 10 (frequent)
- Detectability/Preventability (D): A value assigned on a scale of 1 (very detectable) to 10 (not detectable)
The formula applied is S x O x D, the product of which is an RPN anywhere from 1 (low risk) to 1,000 (high risk). Users are then able to define what is acceptable and unacceptable for the failure being analyzed.
Common DMFEA Mistakes
Like any process, DFMEA is subject to some degree of user error.
Some obvious lapses include never referencing or improving upon completed DMFEA documentation, or applying the analysis inconsistently. Procedurally, there are a number of missteps that can occur like:
- Not understanding the DFMEA scope and objective
- Not going through the process of design control
- Not separating failure mode, cause and effect
- Ranking criteria too closely
- Only identifying problems, not solutions
- Having no control plan in place when a solution exists
Some of these mistakes may be the result of users trying to save time during the long DFMEA process. Sherlock Automated Design Analysis™ software can economize DFMEA testing time without compromising quality or outcomes.
Sherlock and DFMEA
Sherlock is an automated design analysis tool that introduces insight and prediction into product development at a much earlier stage than other methodologies. Instead of physically testing for failures, Sherlock models the design and uses it to provide dependable analysis.
Of specific benefit to DFMEA is Sherlock’s ability to:
- Automate most of the otherwise time-consuming process
- Comply with AIAG, SAEJ1739 and ISO S26262 standards
- Pre-populate the DFMEA spreadsheet by pulling reference designators, component technology and failure mode information from standard design files (i.e., bill of materials, net lists, Gerber, etc.)
Sherlock automates and simplifies DFMEA, increasing the value of this important analysis process across all industries and disciplines in which it is used. Contact us today to find out more or watch our Introduction to Physics of Failure Reliability Methods webinar to discover the importance of DfR and PoF in product reliability.