Food for thought

[captain]

All risks fall into basicly four catagories.

1- High chance of occurance and high probability of catastrophic result.

2- High chance of occurance and low probablity of catastrophic result.

3- Low chance of occurance and high probablity of catastrophic result.

4- Low chance of occurance and low probablity of catastrophfic result.

Make a list of events that could happen and then assign them to which ever catagory you feel it fits best. The ones that fall into catagory 1 and 3 need to be addressed to a higher degree than those in 2 and 4.

Based on my experience I would assign O ring failure to 4 based on the profiles I dive. Someone else may give it a 1 based on the profiles they dive. That is what makes risk not a one size fits all situation.

 

[Taipeidiver]

Those categories are standard for carrying out risk assessments for a variety of applications. My own application (the construction of high speed railways) uses a process called "systems assurance" based on the requirements of EN50126 to identify and evaluate risks in systematic manner. Items in your Cat.1, 2 or 3 require a design modification, or an operational / maintenance procedure to mitigate them into your Cat.4. The idea is that, when a project goes operational, the only residual risks are in your Cat.4.

These principles can definitely be applied to diving, and probably already have, and I'd be interested to see the results of any studies which have been carried out.

 

[Nemrod]

There have been no critical studies to my knowledge because diving as an undertaking is driven by Dogma. There is a guru and the guru has his followers. Critical thinking is totally missing thus why we see such strong infiltration into open water sport diving of cave and tech diving methods and equipment and styles. When you question the dogma, such as why all of sudden do we need to access the valve in open water single tank diving or why do we really need a BC or why do people use so much weight or why is all black better than not all black and why an open water diver needs a 7 foot long hose on his primary and a can light and on and on you will be pounced upon. How dare question the guru's dogma. Not a very large number of people are serious divers and there is no AOPA (Aircraft Owners and Pilots Association) or EAA (Experiemtal Aircraft Assoc) equivilents etc for divers. N

 

[captain]

Those categories are standard for carrying out risk assessments for a variety of applications. My own application (the construction of high speed railways) uses a process called "systems assurance" based on the requirements of EN50126 to identify and evaluate risks in systematic manner. Items in your Cat.1, 2 or 3 require a design modification, or an operational / maintenance procedure to mitigate them into your Cat.4. The idea is that, when a project goes operational, the only residual risks are in your Cat.4.

These principles can definitely be applied to diving, and probably already have, and I'd be interested to see the results of any studies which have been carried out.

Identifying risk in a systematic order is exactly my point. Just to say somthing is a risk don't do it without without considering chance of occurance and result is like the joke of the person who goes to the doctor and tell the doctor it hurts when I press here and the doctor says just don't press there

 

[do it easy]

Thanks Captain. Now I have a way to quantify the things that scare the cr@p out of me versus the things that merely keep me awake at night.

What you presented seems pretty straight forward and obvious. I'm still wondering why I hadn't thought of it sooner? It's a great tool for analyzing possible failures so that whenever gear/dive decisions need to be made, they can be made in the context of whether the consequences are safer or not.

 

[Uncle Pug]

Captain says analyze and catagorize... Taipeidiver says mitigate.

I like it.

 

[jeckyll]

That's a very nice way to categorize risk. For any sport / situation really.

 

[The Chairman]

Nemrod,

My Karma ran over my Dogma!

In reality, we have a little mouse that is loose in our cupboards: the mouse of complacency. Once we take a chance and get away with it, it doesn't look like that big of a problem. IOW, most divers categorise the various threats by their "Feelings" and not by being objective. Unfortunately, feelings are seldom consistent and prone to being completely WRONG. Sometimes they are ALL we have to go on, but whenever possible, we need to rely on facts, and not feelings.

 

[captain]

Nemrod,

My Karma ran over my Dogma!

In reality, we have a little mouse that is loose in our cupboards: the mouse of complacency. Once we take a chance and get away with it, it doesn't look like that big of a problem. IOW, most divers categorise the various threats by their "Feelings" and not by being objective. Unfortunately, feelings are seldom consistent and prone to being completely WRONG. Sometimes they are ALL we have to go on, but whenever possible, we need to rely on facts, and not feelings.

And the facts are???

 

[MikeFerrara]

All risks fall into basicly four catagories.

1- High chance of occurance and high probability of catastrophic result.

2- High chance of occurance and low probablity of catastrophic result.

3- Low chance of occurance and high probablity of catastrophic result.

4- Low chance of occurance and low probablity of catastrophfic result.

Make a list of events that could happen and then assign them to which ever catagory you feel it fits best. The ones that fall into catagory 1 and 3 need to be addressed to a higher degree than those in 2 and 4.

Based on my experience I would assign O ring failure to 4 based on the profiles I dive. Someone else may give it a 1 based on the profiles they dive. That is what makes risk not a one size fits all situation.

Very similar to what we (when I still had a job in manufacturing) refered to as FMEA or "failure mode & effects analysis". We often did seperate FMEA's for designs and processes. However, probability and severity can't really be described as just high or low. Well, they could but I wouldn't expect that to result in a very useful system. They really vary on an infinate scale. To compromise they are usually graded on a numbering system like maybe 1 to 10 or 1 to 20. Sometimes a failure mode is rated by multiplying the probability score with the severity score. Depending on the score and the type of product/effect specific actions are required. As Taipeidiver indicated, the required actions could range from ignoring the failure mode (in the case or one with a low probability and a low severity) to requireing a design change, process change or 100% testing.

As a process diving is just too oporator dependant to be reliable or greatly effected by a system like this. The root cause to any process failure in diving would almost always be oporator error. The corrective action to any process failure would be to correct oporator behavior. How? Training and practice of course.

In practice systems like this are often used to document what we did and why rather than guide our efforts in actually doing it. The business folks like it because they can almost understand it but the technical folks just go through the motions to satisfy the system. The exception of course might be a few young or inexperienced engineers who don't get the joke yet and still spend all their time in things like this documenting what they would do if they ever got the documentation done and had time to do anything. LOL

If I had to explain/justify how I dive to an MBA that doesn't know anything about diving I might use something like this to do it but I don't need it to dive. Numerous methods for identifying and dealing with dive related risks are already outlined in some diving texts and part of the way we learn to plan a dive. Some of it is built into the very way we are (or should be) trained and what we're trained in. I doubt we need to re-invent the weel by bringing the systemitis of modern failing industry into the picture...just not the example to follow and not the thing to be spending your time on.

Besides, look what FMEA, six sigma, SPPD, tops, my favorite ISO or any one of a million other systems like this have done for American industry. LOL