Re: [DNA-BOF] Comment required: Goals or Requirements for DAD, DNAv4,DNAv6?

[Pekka Nikander <pekka.nikander@nomadiclab.com>]

Greg Daley wrote:
> Pekka suggested that we may want to have a DAD Optimization
> Goals document which combines problem statements and
> goals(requirements)?
> 
> One of the cited reasons was the well defined nature of
> this task.
> 
> What do people think about this?

Since I suggested that, I am apparently in favour of the
suggestion... :-)

> I'm still guessing that DNAv4 and DNAv6 need some
> more analysis to ensure that we cover the issues there.
> 
> DO people think that problem statements and goals/requirements
> should be separate there?

I don't have any strong opinion on this.

> Do people think we should change the requirements documents
> in the charter work list to goals?

Personally, I don't like the word "requirements" much.  To me,
it looks like many people take it too literally, and complain
when one or more requirements cannot be fulfilled, or conflict
with each other.  I've seen at least one WG (multi6) to stall
for a long time partially because of this very reason.

Furthermore, I don't really believe in staged engineering
where you first define a set of requirements and only then
try to fulfil them.  The resulting systems tend to be overly
complex and rigid.

In my humble opinion, goals (or requirements) are good for
aligning people's thinking.  Futhermore, they can be
used as partial evaluation criteria in beauty contests.
However, I also think that things like architectural simplicity,
flexibility, and modularity should also be considered.

If goals are defined to be used as evaluation criteria, then
it is somewhat unfair to allow any people that propose solutions
to participate in defining the goals, since such participation
may be biased.  However, as long as there are little IPR or
other commercial interests, I don't see this as a real issue.

On the other hand, if there is real controversy on what is
the problem, then separate problem statements and goals
probably help.  I haven't really followed the DNA specific
discussion so that I could make comments on that.

--Pekka Nikander