[SystemSafety] Fwd: Re: CbyC and unit testing

[Olwen Morgan]

On 03/07/2020 22:17, David Crocker wrote:
> I've been involved in producing CbyC tools for many years. My view:
>
> - If the complete tool chain (CbyC tools, compilers, linkers etc.) and 
> hardware work as intended, the software will perform according to the 
> specification at the unit level.
> - The primary function of unit testing in a CbyC process is to check 
> that the tools and the process used to combine them are working as 
> intended. We expect no errors to be found by unit testing. If we do 
> find errors, there is something wrong with the tool set or the process.
> - If we use the same tool set and process for enough projects, we may 
> gain enough evidence and confidence in them to omit unit testing in 
> future projects using the same tool set and process.
>
At last, the kind of measured statement that I was seeking to elicit!

I agree entirely with David that in a CbyC process, the aim of UT is to 
test that the tool chain is working as intended.


Olwen