Definition
A branch of FMEA that identifies potential failure modes, effects, and causes during the product design phase, and evaluates risk using severity, occurrence, and detection to drive design preventive actions.
In detail
DFMEA is the application of FMEA in the design phase, focusing on 'how the design might fail, what impact customers will experience, and what the design causes are,' differing from PFMEA, which focuses on manufacturing process failures, and from DFMA, which is oriented toward manufacturing and assembly. The team should complete the analysis before design freeze, use experiments, simulations, or design changes to reduce high-risk items, and record the residual risk after actions; merely calculating an RPN without changing the design does not constitute completing DFMEA.
Example in practice
The locking mechanism of new equipment might loosen under vibration. The team rated the customer consequence as high severity in the DFMEA: structural redundancy and material verification reduce the occurrence rating, while durability testing improves the detection rating. After the measures were completed, they re-scored and retained verification evidence, so the risk was eliminated before design freeze, rather than being discovered during mass production inspection.