Visualising progress - an analogy

[Andy Greener <andy@gid.co.uk>]

A little something to stimulate discussion around Agenda item 3 for
today's conf call. I've slipped into analogy-mode - if you find it
useful to think this way (as I sometimes do) then you may get something
out of it, if not, then nothing's lost. I hope the point comes across
regardless...



Tax XML TASC - where are we going?

If you liken the task of the Tax XML TC as a whole to designing and
bringing to market a car/automobile then the job of the BASC is to
understand what is required (obvious stuff like wheels and an engine)
and what will make it sell (getting from A to B quicker and safer than
the competition for instance, comfortable seats, sat-nav, etc, etc).
This involves, amongst other things, understanding the market,
understanding the available technology and understanding the environment
it will be used in.

In this context, the job of the TASC can be likened to that of the
engineers tasked with designing and building the prototype. The
appropriate components have to be acquired or made, assessed for
individual suitability and their compatibility with each other, and
then assembled into a working artefact. Much early prototype work
might be thrown away once wind-tunnel testing starts, and it may be
recognised that certain key components or ideas are going to need
significant further development in their own right.

The engineers cannot complete this task until they know what it is
they are building and what purposes it must serve. However, various
technologies are pretty much a given once some early design decisions
are made, and it is the job of the engineers to understand potential
technologies and how they might be utilised in the design of this
particular vehicle. Engineers can also dream about what they'd do
given unlimited funds and a clear run at the problem, if only it
would sell :-)

So, where are we currently?

Well, some early requirements have been determined, but it's too early
to say what the vehicle will look like or how it will handle. We know
something about the environment it is to operate in (lane widths, car-
park roof heights, road surfaces, bridge strengths, etc), and also
something about the other pieces of technology it has to work with
(GPS satellites, FM radio stations, wireless key fobs, etc).

We know what materials we're likely to use in the construction, and
roughly how they'll go together. There are components that we could
use, and which we are investigating or experimenting with. We have an
idea of which engine we might employ, but we don't know for sure yet
if it will meet the "business" requirements - will it be cheap enough,
powerful enough (or maybe too powerful) or light enough.

Progress cannot be judged by how many decisions have been made or are
left to make, and neither can it be judged by the components that have
been decided upon or incorporated into sub-assemblies. Progress at this
point is measured by how much is understood about the final product,
and how much is not.

Once the business requirements and the specification have been bottomed
out work on the prototype can begin in earnest. Only at that point can
progress begin to be measured by how many components have been integrated
and tested individually and in unison, and what the vehicle is starting
to look like.

Where do we want to be, and when?

Obviously, as engineers we want to be at the point where we have a
complete set of requirements from which we can assist in the development
of the specification, since the production of the finished article
is all downhill from there. Equally obviously, we're not at that point
yet, and are in large part dependent on the BASC for getting us there.

My guess is that we need to be at this point before the second face-to-
face meeting of 2004 (ie around May). January is probably too soon for
the BASC, though I'd be happy to be proved wrong.

Meanwhile, however, we work in the loose framework we do have, assessing
likely looking or useful technologies, absorbing information and
understanding how components can be fitted together. There are a
number of these assessments that we can complete by the end of the
January meeting, and we should be able to make a stab at defining what
they are.

	Andy
-- 

Andy Greener                         Mob: +44 7836 331933
GID Ltd, Reading, UK                 Tel: +44 118 956 1248
andy@gid.co.uk                       Fax: +44 118 958 9005