EBME Forums Forums Management Medical Equipment Management Risk-Based PM

Risk based PPM certainly has benefits, in the example of the Tuffsat I agree with Dave C there is no point in routine testing of this device, PPM here would not reduce breakdowns. Maybe its time to catagorise equipment based on risk and allocate resourses acordingly.

Primum non nocere!

Thanks for "publishing" (and be damned?) there, Dave. I will take a detailed look at it all later.

But immediately I should say that, noticing that you have kindly acknowledged Ottawa there ... I also notice (in the downloads) elements of both Larry Fennigkoh and Brigid Smith (F&S) and (more importantly) Mike Capuano and Steve Koritko (C&K), who expanded upon the original F&S idea. Perhaps I had better mention the later work of Binseng Wang and Alan Levenson (W&L) as well!

My point being, of course, that (as usual) we are "standing upon the shoulders of giants". Which (and on a personal note) just goes to show that some of us old timers are not actually stuck in the past, after all!

But I don't think we should worry too much about "who invented maintenance" (CM, CBM, PPM, PM, RCM ... and all the other acronyms). No single person has that claim, surely (unless it was some old dude back in the days of Noah ... a bit before my time, then). But the real point is to build upon what has gone before, in the light of experience and evolving (improving?) technologies ... and then move forward!

No ... (but) they are the top line. That is, the starting point, the bench mark, or base line.

An interesting post, Dave. And I'm sure we could all argue till the cows come home about which risk factors to consider, their relative weightings, and (importantly ... and as you point out, who gets to fill in the form) ... but it seems you have left it to me to deliver the punch line! Which is odd (or perhaps you are just being kind), as the Big Clue has already been given ...


Excellent as Leo de Kryger's .pdf document is, it doesn't appear to mention this, which I also find a bit odd (disappointing, even).

With a database system (such as, dare I say it, the TaskMaster program, these past twelve years) that include Risk-based PM with automatic interval adjustment capabilities, after running through a number of PM cycles the PM interval for each item of equipment will be automatically adjusted (extended usually, but could also be shortened) according to (yet more) rule-based criteria.* The longer the PM regime continues (that is, over the years) the system will settle down and tend towards equilibrium, happily running along with "ideal" (that is, according to all the rules pertaining) intervals for each item of equipment.

To paraphrase Goldilocks ... not too much, not too little, but just right. That is, ending up with different intervals for various equipment (and even amongst equipment of the same genre) ... thereby, of course, opening up yet another can of worms (along the lines of "do we PM all three machines today, or come back and do the third one when it falls due, the week after next"?)!

In theory (at least) towards the end of an equipment item's life, or at least when it starts to become less reliable, the system kicks in again to shorten the PM intervals (even perhaps to a point of highlighting the need for replacement).

Because of the number of tricky variables involved, it is difficult to portray the full potential of the Risk-based Model in two dimensions (without resorting to endless examples). Because it is a dynamic concept, a computer program is the best way of demonstrating what it is all about.

This level of refined efficiency is attainable. The "secret" (difficulty, wizardry ... whatever) is in thinking through and establishing the rules (criteria) and contriving the algorithms, and then setting the whole thing up! As may be obvious, I spend a fair amount of time pondering such issues myself, and (as always) invite feedback, constructive criticism, and collaboration!


Best leave that old chestnut for another thread, I think, Dave. And, as I have said a few times before (and I should imagine that most will already agree), that's not the only reason we pursue equipment PM in the "healthcare industry" anyway (in fact, come to think of it, it's a bit of a red herring, that one)!

But lastly (for the time being), here is a quote from Section 8 of DB-2006(05) (which gives official guidance for "Managing Medical Devices" in the UK):-


* See posts yet to follow about what these are likely to be ... but let's keep these posts in the realm of bite-sized chunks!

Looking again at the classic formula on page 13 of "Leo" (or, indeed, once again here), it wasn't clear to me how the Form and the Formula actually matched up. Then I realised that they don't at all. In fact the formula* is simply included (by Leo) as an example of the JCAHO model. Another red herring, then!

Meanwhile, the Form calls for simple addition of the scores.

Meanwhile, here's another resource. The same good old stuff, just (nicely) presented in a different way (Win-4 ... or Six-Sigma?).

And here's yet more bedtime reading!

* This is a variation to what I believe is known as the FSV. That is, the Fennigkoh and Smith Variations, from the classic paper published by them in 1989 (and from which most of the subsequent work on Risk-based PM is founded).

One of the really nice things about the Risk-based model is that it presents an opportunity to arrange (and conduct) PM in order of Priority. To my mind, this is a Big Plus (and is the way I would always go about things myself ... given a free hand, that is).




So it can be seen that (once the PM becomes due) the Risk figure remains the major factor, but the overall equation becomes influenced also by the passage of time beyond the date due. That is, the Priority increases each day until the PM is completed. The PM interval also has influence over Priority if the interval is altered (lengthened, shortened). The idea being that the higher the Priority figure, the more at risk or significantly overdue the PM procedure is.

Notice that at the time a PM is carried out, "the system" (program) should re-set Priority to Risk (and never allow it to fall below Risk). That is, matters are arranged so that Priority is always equal to, or greater than, Risk. The Priority figure only starts to become greater than Risk once the PM interval has been reached (and passed).

One of the arguments sometimes brought out against this approach is that, by concentrating on each successive High Priority PM (and, don't forget, we're talking about a dynamic system here, that changes with the passage of time) that low Risk items may never get seen. The answer to this is that, given enough (passage of) time, even those items that started off at a low Risk level will slowly climb up the list. Just check out the formula!

Here is a list of Six Sigma Corporations - some familiar names on that list....

Indeed! But I don't see the NHS mentioned ...

"Real" industries are full of this stuff. For example (and there are many others), how about ... The Unipart Way?*

* Yet another system aimed at reducing waste and eliminating activities which do not add value.

Paul, (or anyone else for that matter), with regards to the Estates Journal article, would you have contact details for anyone @ Papworth who was/is connected with this work? I would like to contact them and explore this further.

Any forum folk working there?

Ta,

Yes, Paul himself, for starters!

Thanks Geoff, straight to the source !