Agile specifications (was: Managing Extreme Programming)

Alleman, Glen B. said:
> As one moderately close to the satellite biz, what would you 
> see as process improvement for shortening the build cycle of 
> say on-board position holding software? Ball builds 
> spacecraft from a "bus" POV in that the basic frame for the 
> craft is standard off the shelf and the instrument adaptors 
> are defined in advance.

"Standard off the shelf" for spacecraft is a bit less highly evolved than it
is for many earthly endeavors.  Because of the long lead time to certify any
new components for flight, evolotion of those components in inhibited.

A friend who still works at Goddard tells me about a British spacecraft
builder who's a lot more agile in their hardware development.  Their
hardware interfaces are apparently more evolved than Ball's and allow them
to mix-and-match or create new modules in a much shorter timeframe and for a
lot less money.
 
> What's defined at time of the order is the detailed behavior 
> of the instruments and the onboard processing as well as the 
> data link processing onboard and on the ground.

Yes, and the design of the instruments could be better if they depended on
what the Principal Investigator knew 6 months prior to launch rather than 2
to 5 years prior to launch, but there's a long process to get a project
approved, get funding, build the hardware and software....  Spacecraft
hardware and onboard software tends to be *very* primitive.
 
> What organizational hurdles have you come across that slow 
> down the process that could be improved? How could "agile" 
> make these improvement from your experience? 

It's been several years since I've had direct contact with any NASA
projects, and I'm not an expert at Organizational Patterns.  I don't think
I'm the person to advise on how it can be improved.  You don't have to be an
expert, however, to see that there's room for improvement.  Or that many
formalities are done for show, without doing the underlying work that's
intended.  I've seen "design" documents that had been reviewed and "signed
off" but didn't answer many important questions.  They dodged the unknown
issues with language.  It's ludicrous to say that these particular documents
"specified" the design.

I'm reminded of a tale I heard about a long-ago medical exam.  The proper
answer to "Why does morphine cause a person to be sleepy?" was "Because it
has a dormative principle."  Of course, this is a tautology and explains
nothing.  It just says that morphine makes a person sleepy because it's been
found that morphine makes people sleepy.

 - George

> > -----Original Message-----
> > From: Dinwiddie, George [mailto:[email protected]]
> > Sent: Tuesday, January 14, 2003 10:45 AM
> > To: [email protected]
> > Subject: RE: [xpAdoption] Managing Extreme Programming
> > 
> > Alleman, Glen B. said:
> > >Building code for satellites or decommissioning former 
> bomb factories 
> > >is probable not such a domain.
> > 
> > I've never been near decommissioning former bomb factories, 
> but I make
> the
> > argument that building code for satellites *is* such a 
> domain were it
> not
> > for the organizational hurdles involved in agreeing on the
> requirements
> > and
> > the long procurement and testing pipeline for the hardware.  It's 
> > interesting to speculate that, were NASA to implement and trust more
> agile
> > processes (not "smaller, faster, cheaper" which was just used as a
> mantra
> > to
> > cut corners), then the organizational hurdles could be much smaller
> and
> > the
> > whole process more agile and less "predefined".  This is 
> what I meant
> in
> > my
> > previous message.
> > 
> > I will agree with you that, in practice, it's not going to 
> happen that
> way
> > in the near future.
> > 
> >  - George
> > 
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