What is DFMEA and why it is crucial for your company?
What is DFMEA?
DFMEA is Design Failure Mode Effect Analysis.
To put it simply, it’s a process followed by the engineering team to identify all the potential failures, their impact and figure out ways to mitigate the risk by implementing alternate plans.
Most of the time, the design engineers do brainstorming to visualize the potential failures and implement certain features/processes in design to eliminate risk.
However, this is easy for a small and less complicated product. Imagine you are a car manufacturer and have several teams working on different sub-assemblies. In that case, it’s unlikely to find all potential failures.
The need for DFMEA was first identified by rocket scientists and engineers in the 1950s, as the Root Cause Analysis (RCA) wasn’t really going well for them. The failure would usually lead to an explosion and would destroy all evidence.
The DFMEA can be done for a part, a component, or a process.
The typical DFMEA document consists of 7 sections as shown below,
Let’s understand more about the titles in each cell,
Item & function: The item could be a part/product/process. The function is the description of the item and what it does.
Requirement: It tells what things were considered before starting the development.
Failure mode: This tells what is causing the problem.
Effect of failure: What damage it can make to other components/processes.
Severity: This can range from 1 to 10, 10 being the highest, and can be related to safety.
Class: The class might be related to material or environmental sensitivity, e.g. hazardous material.
Potential cause: Identifying what may cause the failure.
Prevention control: Current method of detecting the failure.
Occurrence: Frequency of the failure happening on a scale of 1 to 10. 1 is very rare and 10 being most frequent.
Detection control: The method/mechanism used to detect the failure.
Detection ranking: How easy it is to detect the failure before it happens on a scale of 1 to 10. 1 being very easy and 10 being extremely difficult.
Risk priority number (RPN): The RPN = Severity x Occurrence and Detection ranking (sod).
Action: The action that needs to be taken to mitigate the risk.
Responsibility: The name of the person who will own this action.
Target finish date: estimated completion date.
Actual finish date: this document will be updated later when we know the actual finish date is known.
Severity: The severity ranking will be updated here after the implementation of the action.
Occurrence: The occurrence ranking will be updated here after the implementation of the action.
Detection: The detection ranking will be updated here after the implementation of the action.
RPN: The RPN will be updated based on the new severity, occurrence, and detection rankings.
An example of how Fasal Hardware Team does it,
The action was taken on the parts with higher RPN and the revised RPN can be seen in the last column. Please observe even though the severity has been the same, the occurrence and the detection have been changed, which eventually mitigated the risk of failure.
Why implement the DFMEA?
The design failures may result in dissatisfied customers, delayed product launches, the financial burdens on companies. This is why prevention is always better than cure.
Without DFMEA, all failures will not be discovered until validation and trial production, and some failures may not be identified till production launch.
Who is responsible for DFMEA?
Ideally, it should be the Product Design Engineer who manages the DFMEA. However, product managers who have in-depth knowledge about the product, process, or system design may as well manage.
The stakeholders or rather team members are the key people from, Product R&D, QC & Testing, Engineering, Production, Supplier, Customer Success, Purchase, Assembly.
When to start DFMEA?
It should be initiated during the design phase. The time and cost of developing the countermeasures at later stages are much higher than that of earlier stages.
Observe the cost of countermeasure is maximum at the production launch.
DFMEA has been a vital part of industries. We at Fasal understand it very well and make sure that we implement it right in time.
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