[SystemSafety] Software reliability (or whatever you would prefer to call it)

[Martyn Thomas]

I agree. That's why I added the point about explicit assumtions before
using such measurements to predict the future.

There is usually a hidden assumption that the future input distribution
will match that encountered during the measurement. But it's hard to
justify having high confidence that such an assumption will prove correct.

Martyn

On 06/03/2015 12:32, Derek M Jones wrote:
> Martyn,
>
>> The company calculates some measure of the amount of usage before
>> failure. Call it MTBF.
>
> Amount of usage for a given input distribution.
>
> A complete reliability model has to include information
> on the software's input distribution.
>
> There is a growing body of empirical work that builds
> fault models based on reported faults over time.  Nearly
> all of them suffer from the flaw of ignoring the input
> distribution (they also tend to ignore the fact that
> the software is changing over time, but that is another
> story).
>