[SystemSafety] IEC 61508 Committee Draft of Edition 3 published

[Peter Bernard Ladkin]

On 2022-10-05 10:39 , Derek M Jones wrote:
> 
>> [PBL] Fair enough. Your view is daft. That is why it is not widely shared.
> 
> The view is not widely shared because it is not in
> the economic interests of those involved to express
> that they are doing involves an element of smoke and
> mirrors
So let's get this straight. Might as well, because there are people on this list who might not have 
the background.

In 1981 a very large and involved book was published by Barry Boehm, SW head of TRW, about TRW's 
experience with costs of SW, including plenty of statistical evaluation, because that is how you 
derive costs in such a company. And how TRW had been evaluating their costs for the previous quarter 
century of bidding on large SW contracts, often for USG.

Contract software development companies such as TRW and IBM collect numbers assiduously and have 
done since the 1960's. They have far more of them than anyone can evaluate and use, but they are 
there. Mostly they are proprietary, because they are used (in TRW's case) for designing bids for 
contracts.

Edward Adams published an evaluation of IBM's most-used SW program (a facility configuration program 
for clients) and its reliability, and the phenomenology of its failures, suitably redacted for 
non-IBMers, in 1984.

There are most definitely economic interests involved. But those interests lead towards accurate 
evaluation of resources and costs, rather than "smoke and mirrors". Just as insurance companies need 
actuaries, it is a necessary part of the business model of any medium-size to large contract 
software development company to accurately evaluate their own work.

Watts Humphrey published a lot of studies for SEI in the 1980's through the 2000's, collected 
together by SEI in 2009. I don't know what "economic interests" might have induced him to engage in 
"smoke and mirrors". But it is surely interesting that nobody has noticed that smoke and mirrors to 
date. Besides, speaking of "economic interests" when someone is working at a USG-funded organisation 
(a government employee at one remove) is pretty wide of the mark. There is lots of such work for 
which your comment makes no sense at all.

When you work at a software engineering research institute, as I did in the mid-late-1980's, this 
amounts to the background knowledge that everyone has.

That said, there are indeed lots of people around who want to make dubious claims about how good 
their kit is and embellish their story with numbers. In every area of science and engineering there 
are the fakes and the embellishers. It's good that there are people like Elizabeth Bix to catch them 
out. There is indeed lots of dubious work around for you to criticise, if you are so inclined. But 
there are oceans between the sort of detailed work Bix does and your trivial comments.

Saying everybody who evaluates SW statistically is an economically-motivated smoke-and-mirrors faker 
is not only daft. It also insults a number on this list who successfully work in the subject. You 
really don't have any grounds to go around insulting better established scientists. You need to up 
your game.

PBL

Prof. i.R. Dr. Peter Bernard Ladkin, Bielefeld, Germany
Tel+msg +49 (0)521 880 7319  www.rvs-bi.de




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