[SystemSafety] A small taste of what we're up against

[Derek M Jones]

Paul,

>> Most systems are short lived.  It is survivorship biases that makes
>> people think systems are long lived.
...

> One datapoint (or maybe two because the two machines concerned utilise
> the same design although exist in separate localities) have operated since
> 1985 and are expected to continue until 2030. This is on the software as it
> was initially installed. Then, the machines operate in a highly regulated
> establishment. I have not heard of anything other than normal mechanical
> maintenance to the equipment being done.

Long-lived systems are all around us.  The ones that die quickly are
not around long enough to receive much attention.

-- 
Derek M. Jones           Software analysis
tel: +44 (0)1252 520667  blog:shape-of-code.coding-guidelines.com