[SystemSafety] A Critical-System Assurance Manifesto

[Peter Bishop]

I think in this case the Bernoulli model is not concerned with
detecting faults/fixing, but about estimating the likelihood that you
will not hit a defective region in the input space (which could in
principle be the aggregate of many faults).

Peter Bishop

On 11/12/2017 14:47, Derek M Jones wrote:
> Peter,
> 
>> * Statistical Evaluation
> Chapter 1, the Urn model.
> 
> The empirical evidence is that the Urn model is not a good
> model of faults discovery.
> 
> The Urn model gives equal weight to each item it contains.
> 
> Some faults are more likely to be discovered than others, while
> other faults are very rarely seen.  This is not the Urn model
> view of the world.
> 
> The Urn model has lots of mathematical history associated with
> it and appears in all the probability text books; which makes it
> a favorite of professors.
> 
> Isn't it about time that people started using a model with a
> closer connection with reality?
> 

-- 

Peter Bishop
Chief Scientist
Adelard LLP
24 Waterside, 44-48 Wharf Rd, London N1 7UX
http://www.adelard.com
Recep:  +44-(0)20-7832 5850
Direct: +44-(0)20-7832 5855

Registered office: Stourside Place, Station Road, Ashford, Kent TN12 1PP
Registered in England & Wales no. OC 304551. VAT no. 454 489808

This e-mail, and any attachments, is confidential and for the use of
the addressee only. If you are not the intended recipient, please
telephone 020 7832 5850. We do not accept legal responsibility for
this e-mail or any viruses.