ISO 14971 Risk Analysis and use of a DFMEA (Design FMEA)

M

medical_eng

#1
Hi All,

ISO14971 stongly suggests (to me at least) that steps 4.2, 4.3, 4.4, 6.2 to 6.7, and 7 would seem to be best structured as a chart (table E.3 on p53 is suggestive of this type of format) to organize it all. Is this how others are doing it? If so, how do you bridge the questions in Annex C with the first column of the DFMEA (and is a 'function' synonymous with a 'characterstic')?

It's almost like the ISO spec calls for one type of analysis (risk, along with the calculation of severity and occurence), then you go off to a parallel universe to do a DFMEA and figure out RPNs. The two don't seem to be well integrated at all.

On a side note, I get the impression that if you follow ISO14971 (and IEC62366 for good measure), that you will end up with a dozen or so cross referencing documents and a bit of a paperwork nightmare. Should this not all organize neatly into the 'Waterfall Design Control' process promoted by FDA in "Design Control for Medical Device Manufacturers"?

Pardon the frustration, but back in my automotive past the line from DFMEA to DVP&R, and DFMEA to PFMEA to Control Plan to Work Instructions was nice and clean. Ah, those were the days...

Here's the litmus test that will determine the correct methodology for me: a material change (a new/different plastic resin for an epi pen for example) should be covered and allow one to logically backtrack to all the risks that such a change would involve. Not all risks, characterisitics, and functions would be affected but a material change would touch a lot of them.

Any guidance from those that have gone to the school of hard knocks would be appreciated! I've read the post from gholland back in January 2009 and most of mmantunes replies elsewhere in this forum on this topic.

Cheers!
 
Elsmar Forum Sponsor

sagai

Quite Involved in Discussions
#4
Hi,
welcome at the cove.

You will find the proper table on page 20, this is a preferred structure.
Here:
DEAD LINK REMOVED - Was: http://www.ghtf.org/documents/sg3/sg3n15r82005.pdf

Hopefully the content of that document helps you to clarify your questions.

Regards
Szabolcs
 
Last edited by a moderator:
M

medical_eng

#5
Hi Szabolcs,

Actually I knew about this document already but I gave it another read-through just now per your suggestion.

Perhaps lets deal with this first: How does one link the questions in Annex C of ISO14971 to the charts of E.1, E.2, and E.3 of ISO14971.

Then, how would one write it all up such that a material change (given as the first example on pg12 of the GHTF doc) can be properly evaluated for risk (as a test case)???

Surely others have had to cross this bridge, so to speak.

Help!
 

sagai

Quite Involved in Discussions
#6
Hi!

How does one link the questions in Annex C of ISO14971 to the charts of E.1, E.2, and E.3 of ISO14971.
Annex C is about the suggestion how you can identify "any foreseeable hazards". This is rarely one more points to consider and this Annex gives a good guidance how to make it.


What you basically have to have as regard to regulatory submission (TF/510k docs) is a risk analysis.
The well structured spreadsheet like format is in the ghtf guidance (at the end as far as I can recall, they call it Risk management file, I guess).
Its structure can be extended based on your company practice and tailoring needs.

Okay ... :cool:

Now what we need is the list of hazards in order to let start working on the risk management file.
E1, E2, E3 are also rarely examples, the well structured list is in the MDD (!) as essential requirement and YOU have to decide for each, whether or not applicable to your device.
I have attached (originally I have decided not to :) ) an example, you can use it as is, I only would warn you, this is based on the MDD for invitro, if your device is not, than you have to check the essential requirements in 93/42/eec and update accordingly.
Actually, for Canada for example, there is a differently structured hazard list, so for each country, you should check the regulation.
For US, this list is fine, +any foreseeable hazards, + usability related.
In general, the non applicability of hazard also should be rationalized, so you can not say, you do not list, you shall list, say no and say why you considered it as not applicable.

As regard to material change, I think the effect of the change should be analyzed, the impact on product safety.

Regards
Sz.
 

Attachments

#7
We use a list, like Sagai's attachment, to indicate how each of the Essential Requirements of the MDD are addressed.

Then our risk report has 2 main sections - the first addresses the questions from annex C of 14971. This makes sure that things like 'Intended Purpose' are fully answered and gives solid background of how things are done.

Then we use the headings from table E1 (energy hazards, biological/chemical, operational, information) to categorise each hazard we can think of, using the tables of annex E as one source. Another useful source for operational hazards is 60601-1-6/62366. Then rank it for severity and likelihood, according to your set parameters and analyse the result.

Any materials change could then be checked of against the ERs and the answers to the risk questions.
 
M

medical_eng

#8
Okay, I've done some more work on my end and some searching on the internet (including an FDA presentation no less) and have come to this firm conclusion:

RISK ANALYSIS DOES NOT EQUAL A DESIGN FMEA!

Perhaps old news to many of you but it was a new thought to me. However, no one seems to see the need to follow the thought any further. Everywhere I look, many sources state the above, go on and on about 'risk analysis', then talk at length about FMEA's and FTA's but then NEVER suggest how everything should be integrated together. It's a big gap out there, IMHO.

It seems quit clear that when a risk analysis needs to be done there are several methods available to determine 'Hazards'. Here's where a FTA and DFMEA come in, from my research: structured methods to determine ***hazards***. Hazards, apparently, can also be determined from expert review and group brainstorming with suitably qualified individuals.

Here's where I started to go out on my own.

I have devise a system whereby I have a chart to organize and list out all the Risk Management Tasks (a structured chart with headings very closely aligned with Figure 1 on page 6 of ISO14971), and I also have a second chart, a standard DFMEA, to determine hazards from device failures (a DFMEA 'Effect' = risk analysis 'Hazard'). The DFMEA 'Effects' are copied over into the risk chart under the heading 'Hazard'. It is easy to see that a medical device can have hazards from normal use, incorrect use, off-label use, and also specifically from device failures (ie: from a structured DFMEA analysis).

On the DFMEA I have Design Control: Prevention/Detection, and on the corresponding line of the risk chart I have "Risk Control: Inherent Safety by Design". The risk control chart cell points back to the DFMEA when the risk control measure is a design task (prevention) or testing task (detection). It doesn't point back if the risk control for the device failure mode is, say, "Information for Safety" if that happens to be the case.

This seems to work well, except the back linkage to the DFMEA for Risk Control makes it slightly clumsy plus you need to maintain two charts. Oh well, so be it.

(I reviewed the GHTF chart and though it has a handy method of cross referencing verification, it otherwise falls short in many other ways.)

So my litmus test is that this system works if a material change occurs, as any device failures due to material would show up in the DFMEA as perhaps a testing failure on a bench test and then be linked to the risk analysis through Effects=Hazards. If a usability test is done and they break the medical device, it can likewise be traced back to material selection as a potential root cause.

As a counterpoint, I can also go through a full and proper risk analysis and never perform a DFMEA but rather do a FTA or HAZOP analysis to determine hazards. Again, that seems to be part of the key: pick a method to determine hazards.

Last but not least, as a contrived example, a device or object will break because (a) it's not strong enough; or (b) to much force was used on it. The DFMEA looks at it from the perspective that perhaps an insufficient strength material was used in the design (or it's too thin, etc.) while the risk analysis examines the likelihood that a normal user will apply sufficient force to break a fragile feature. Both situations require the same countermeasure: make it stronger!

All is now well :)

So my (last) 2 questions:
1) Does this all make sense to you out there as a workable technique?
2) Why has no one else ***explicitly*** spelled it out this way (the integration of techniques), despite all the information available on 'Risk Management'?

Thoughts???
 
S

Sujith Kallur

#9
I think the answer for your question about gap is business related. You don't give your complete recipe to anyone. You just give a part of it to make someone interested and then once they are in, they realize they need help. Then consultants come in with helping hand and big quotes. :bonk:
 
Thread starter Similar threads Forum Replies Date
M ISO 14971:2019: Criteria for overall residual risk ISO 14971 - Medical Device Risk Management 11
R Risk control measures as per ISO 14971 ISO 14971 - Medical Device Risk Management 6
R Identify Medical Device characterstics as Annex C of ISO 14971 Risk Management ISO 14971 - Medical Device Risk Management 5
A ISO 14971 PFMEA Manufacturing Risk ISO 14971 - Medical Device Risk Management 2
K Overall residual risk according to ISO 14971:2019 ISO 14971 - Medical Device Risk Management 5
M Risk Analysis Flow - Confusion between ISO 14971 and IEC 62304 IEC 62304 - Medical Device Software Life Cycle Processes 8
J ISO 14971 applied to ISO 13485? Low risk class 1 devices ISO 13485:2016 - Medical Device Quality Management Systems 5
P Risk acceptability alignment between ISO 14971 and IEC 62304 IEC 62304 - Medical Device Software Life Cycle Processes 6
S ISO 14971 Risk Management - Questions for Hazard identification ISO 14971 - Medical Device Risk Management 2
R The difference b/w FMEA & Risk analysis as per iso 14971 ISO 14971 - Medical Device Risk Management 8
D Risk management according to ISO 14971 - When to document risk controls? ISO 14971 - Medical Device Risk Management 10
D Where does FMEA fit in your ISO 14971 Risk Management process? ISO 14971 - Medical Device Risk Management 13
Q Information for safety EN ISO 14971:2012 - Customer Risk Reduction ISO 14971 - Medical Device Risk Management 6
M Informational ISO TC 210 JWG 1 meeting in São Paulo – Revision of ISO 14971 and ISO TR 24971 – Medical Device Risk Management Medical Device and FDA Regulations and Standards News 0
S In a risk analysis, how can we tie mobile app security breach to ISO 14971? 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 4
M Example ISO 14971 policy and risk criteria ISO 14971 - Medical Device Risk Management 0
D Rationale for Risk Acceptability Matrix - ISO 14971 ISO 14971 - Medical Device Risk Management 9
Y Training as a risk control for ISO 14971 ISO 14971 - Medical Device Risk Management 13
W Risk Benefit Analysis - ISO 14971:2012 Requirements ISO 14971 - Medical Device Risk Management 27
C What is the difference between "Overall Risk" and "Risk"? (ISO 14971) ISO 14971 - Medical Device Risk Management 10
S Organizing Risk Analysis and Controls for a New Medical Device (ISO 14971) ISO 14971 - Medical Device Risk Management 4
A Is Risk Management Process compliant to ISO 14971 in absence of Hazardous Situations? ISO 14971 - Medical Device Risk Management 5
N Risk Severity Estimation for Medical Devices as per ISO 14971 ISO 14971 - Medical Device Risk Management 12
Marc Are you looking for ISO 14971 - Medical Device Risk Management? Risk Management Principles and Generic Guidelines 1
J Does anyone have an example of Risk-Benefit Analysis per ISO 14971? Other ISO and International Standards and European Regulations 2
M ISO 14971:2012 - Verification of Implementation of Risk Control Measures ISO 14971 - Medical Device Risk Management 12
N ISO 14971 Risk Analysis - Sections 4.2 and 4.3 ISO 14971 - Medical Device Risk Management 2
D ISO 14971 - Risk Analysis Best Practices ISO 14971 - Medical Device Risk Management 5
A ISO 14971 Figure E.1 that starts with Hazard and ends with Risk ISO 14971 - Medical Device Risk Management 3
A Risk Acceptance Criteria in ISO 14971 ISO 14971 - Medical Device Risk Management 19
M Risk Management (ISO 14971:2007) Internal Audit Checklist ISO 14971 - Medical Device Risk Management 7
K RISK ANALYSIS SAMPLE according to Annex ZA of EN ISO-14971-2012 Other Medical Device and Orthopedic Related Topics 1
K What is the policy for Risk Acceptability per ISO 14971 ISO 13485:2016 - Medical Device Quality Management Systems 2
M The Sequence of ISO 14971 Risk Analysis Activities ISO 14971 - Medical Device Risk Management 14
Sam Lazzara ISO 14971 Clause 7 - Evaluation of Overall Residual Risk Acceptability ISO 14971 - Medical Device Risk Management 3
C Risk Analysis of a "Medical System" according to ISO 14971 ISO 14971 - Medical Device Risk Management 5
N ISO 14971:2007 vs. 2009 - Which Risk Management Standard is still accepted in the EU Other ISO and International Standards and European Regulations 2
E ISO 14971:2009 Risk Management Requirements CE Marking (Conformité Européene) / CB Scheme 2
M ISO 14971 Medical Device Risk Management FAQ ISO 14971 - Medical Device Risk Management 43
M Risk Management Plan Template - ISO 14971:2007 Compliant ISO 14971 - Medical Device Risk Management 13
C Scope of Risk Management in ISO13485 vs. ISO 14971/EU MDD ISO 14971 - Medical Device Risk Management 2
C ISO 14971 Clause 9 Requirements - Post-Production Monitoring and Risk Management ISO 14971 - Medical Device Risk Management 7
A Where can I buy EN ISO 14971:2009 (Medical Device Risk Management)? ISO 14971 - Medical Device Risk Management 11
Q ISO 14971 Class II Medical Devices - Product Realization & Risk Management ISO 14971 - Medical Device Risk Management 5
J IECEE Guidance Document for ISO 14971 Risk Analysis - IEC EN 60601-1:2005 3rd edition IEC 60601 - Medical Electrical Equipment Safety Standards Series 2
I Medical Device Risk Assessment to ISO 14971 ISO 14971 - Medical Device Risk Management 4
B Application of Risk Management - ISO 14971 for a Tooling Manufacturer ISO 14971 - Medical Device Risk Management 18
M Risk management, ISO 13485 and ISO 14971 ISO 13485:2016 - Medical Device Quality Management Systems 10
G Risk Analysis - Templates of EN ISO 14971:2007 and others ISO 14971 - Medical Device Risk Management 8
M ISO 14971:2007 Risk Management - Class I A Sterile Medical Device ISO 14971 - Medical Device Risk Management 4

Similar threads

Top Bottom