[SystemSafety] What do we know about software reliability?

[Peter Bishop]

On 14/09/2020 15:36, Derek M Jones wrote:
> Martyn,
>
>> How do you then get from the number of fatal defects to a reliability?
>
> You don't.
>
> What it says on the can is an estimate of a particular kind of
> failure.

You might however be able to link it to expected long-term losses if you
include bug fixing after incidents

https://www.researchgate.net/publication/299690777_Does_Software_Have_to_Be_Ultra_Reliable_in_Safety_Critical_Systems

Key parameters are

- number of dangerous defects
- probability a fault is fixed after an incident
- probability of an accident after each incident

Peter

>
>
>> On 14/09/2020 14:46, Derek M Jones wrote:
>>> Fuzzing appears to be a practical technique for gathering the data
>>> needed to
>>> estimate likely number of mistakes that will cause a system crash.
>>> Practical
>>> in that a few months of cpu time is quite cheap these days.
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Peter Bishop
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