Re: Ravenscar Profile and SIL

[Dewi Daniels <dewid@praxis-cs.co.uk>]

In article <3a702206$1@pull.gecm.com>,
  "Brian Jepson" <Brian.Jepson@baesystems.com> wrote:
> In Def. Stan. 00-56 it is the safety functions that are allocated
SILs, so whilst some of the
> functions implemented using the Ravenscar Profile might have a SIL3
requirement it is bad
> terminology to call the comonents of the implementation SIL3.

To be pedantic, DEF STAN 00-56 does require both abstract functions and
components to be allocated safety integrity levels (see 7.4.2). I agree
that allocating SILs to the safety functions is the fundamental part of
the whole process, since the component SILs are derived from the
function SILs (albeit in a slightly complicated way, see 7.4.8).

I also agree that it makes no sense in a DEF STAN 00-56 context to
refer to a S3 operating system or run-time per se, since in DEF STAN 00-
56, a safety integrity level only makes sense when applied to a
specific set of safety functions and safety properties.


Sent via Deja.com
http://www.deja.com/