PHA and DFMEA

Jes890

Registered
Hi All,
Here's a question regarding PHA (Preliminary Hazard Analysis) and DFMEA (Design Failure Mode and Effect Analysis):

"Are PHA and DFMEA considered live documents in processes, and what stages of a project lifecycle are these analyses typically undertaken?"
"Is there any link between two documents?"
 

EmiliaBedelia

Quite Involved in Discussions
This is just my opinion, but this all depends a lot on what your risk management process says and how your design control process works.

Your risk file should be considered "live" throughout the process lifecycle to the same extent that the rest of your documentation is. Generally you'd complete everything iteratively as your risk process should follow along with the rest of the design and process development. Your risk documents should correlate to each other in some way so you may not be able to finalize certain documents until other documents are complete.

Usually the hazard analysis is one of the first things that gets completed as this should feed everything else. The HA would collect hazards associated with the therapy/device type and identify the harm and severity. The hazard analysis is important because the severity assigned to a pre-RCM harm should be consistent across all your risk documents (eg, if your pFMEA identifies the severity as 3 and your dFMEA as 2 for the same hazardous situation, something is wrong). You should also ensure that your PHA reflects any new hazards that emerge throughout the risk process. For example, if you add a blade to your design for some reason, make sure you have captured any risks related to blades.

If you choose to use analysis tools that exist at a "point in time" as part of your initial risk analysis (eg, if you use a fishbone diagram or input/output diagram or something like that), then I don't think you need to maintain those. However, you should be cautious that your risk process is clear about how and when those tools should be used.
 

yodon

Leader
Super Moderator
Just to add on a bit to the excellent response from @EmiliaBedelia, the risk file is a living document as long as your device is in the market. After you start distributing, you need to continually consider inputs from both the production and use (feedback, complaints, competitor products, etc.) to maintain the risk file. You may identify new hazards, learn of new ways to realize risk, recognize that your scoring is not accurate, etc..
 
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