[SystemSafety] Who applies risk acceptance principles - Part 2

[Peter Bernard Ladkin]

Hi Myriam,

thanks for the update.

The 1999 ISO Guide 51 on safety aspects in standards says that standards shall incorporate certain 
processes which it calls cumulatively "risk assessment". This consists of
* defining intended use and reasonably foreseeable misuse
* identifying hazards
* estimating risk
all of which is called "risk analysis". Risk analysis together with the subsequence step
* evaluating risk
is called "risk assessment". After risk assessment, one asks
* whether tolerable risk is achieved
If so, one is done. If not, one is to perform
*risk reduction
and start again at the top.

Guide 51 is currently being modified and I don't know what is in the new version. I suspect it may 
lose its commendable simplicity.

Now, there is nothing in the above which suggests that deriving risk acceptance principles is a 
practice which must appear in a safety standard. Obviously, in deciding whether tolerable risk is 
achieved, one must either apply a set of principles or decide ad hoc. I suspect most people would go 
for principles in the abstract but probably go ad hoc (that is, "what my boss tells me I have to 
do") in practice.

It seems to me like a good idea it would be required that the decision method for "tolerable risk" 
be made explicit. That is, in your terms, that risk acceptance principles were to be explicitly defined.

PBL

-- 
Prof. Peter Bernard Ladkin, Faculty of Technology, University of Bielefeld, 33594 Bielefeld, Germany
Tel+msg +49 (0)521 880 7319  www.rvs.uni-bielefeld.de