Re: Teaching new tricks to an old dog (C++ -->Ada)

["Dr. Adrian Wrigley" <amtw@linuxchip.demon.co.uk.uk.uk>]

On Thu, 24 Mar 2005 22:28:22 -0800, Jerry Coffin wrote:

...
> Programming languages fit into this fairly nicely: when Ada is chosen,
> it's mostly by a relatively large company with adequate funding that
> hires experienced managers, has a clear goal and a reasonable idea of
> how to reach it.

I was particularly focusing on large software projects.  These always
have high levels of resources - perhaps $100m+.  Something like
a Social Security administration system, or an Air Traffic Control
system.  The stakeholders really can't afford to have projects
collapsing at the rate of 50%-70%.

> At the opposite end of the spectrum, if you look at an unfunded startup
> consisting of one or two guys straight out of college who are certain
> that in six months they're going to become billionaires by creating the
> next Netscape, their language of choice is most likely Java, with C++
> in second place, and Ada basically not even in the picture at all.
> 
> It takes only minimal business acumen to figure out which project is
> more likely to succeed -- but even less to realize that IF each had
> chosen the other language, the answer would be unaffected.

You are saying that the large software projects have a significantly
lower failure rate?  And this is obvious to those with business
acumen?  And obvious that the large project's success is independent
of the language choice?

I have not come across any studies that support these "obvious"
findings.  But I haven't looked into this very much, and I'd
be pleased to have pointers to such studies.

Curiously, if the C++ community says language choice is irrelevant
to project success, but the Ada community says it matters, perhaps
managers should always hedge their bets by choosing Ada(?)

I was at a seminar by the project leader of the Canadian ATC system
a few years ago.  He explained all the management and engineering
approaches taken to get the best outcome.  He seemed very proud
to have developed one of the most robust, well budgeted, successful
projects in its class.  This is contrasted to the "issues" which
have arisen in the new US ATC system, or the UK system.
At the end I asked "was language choice a factor in success and which
languages were used?".  He replied that it was almost entirely Ada,
and this played a big role in the positive outcome.  But he didn't
seem to want to introduce the issue in his presentation, because
it could be so controversial.

But again, this is anecdotal evidence.

More tangibly (but at the small end of the scale):

another snippet:

"In one of the few times a manager has performed the same project
several times using similarly experienced teams but with different
programming tools, the use of Ada significantly boosted project
success rates. At SUNY Plattsburgh, Professor John McCormick has
assigned the same real-time programming project to his class for nine
years."

"Working in teams of three or four, McCormick's students must write
15,000 lines of code to control a system that would need about 150
switches to operate using hardware alone. In the five years students
used C, no team completed the project -- even when more than half of
the code was provided. With Ada, however, half of the teams completed
the project before any support code had even been written. With some
support code now provided, three out of four teams finish the project."

In summary:
It simply isn't good enough for a language community to claim
language choice is irrelevant, without giving real-world evidence.
And why would such a claim attract us to the community?

If choice is claimed to be irrelevant, why focus on small-scale
issues like arrays vs. containers or contract vs. non-contract
template models?

Or to put it another way:
How come "more expressive" templates, "better exception handling",
or "less verbose" syntax is not claimed to improve project success?

Maybe I (still) don't get it.
-- 
Adrian