[comp.lang.ada] Reusability

BENNETT@sp.unisys.COM.UUCP (03/14/87)

Having just read the two dissertations on reusability
submitted by Mr. Berard, I find myself wondering about a
couple of things.

First, it seems to me that the Cost-Plus-Fixed-Fee contract
is not, in itself a barrier to the development and use of
reusable software.  On the contrary, by making optimum use
of reusable modules, I could reduce the level of effort
needed for implementation and apply the savings on the front
end of the life cycle.  The net effort would be the same,
but we have reason to believe that increased effort on the
front end of the development will lead to a higher quality
output.

Second, I would like to see some evidence that "object
oriented" methods are better than "functional decomposition"
at facilitating reuse.  It seems that it would be the job of
the designer in either case to recognize those functions or
objects which are candidates for reuse.  I might be
convinced if there were a rigorous methodology for either
functional decomposition or object oriented design which
would result in two different designers producing identical
designs from the same input.

Third, requiring that "every piece of code produced for a
project, be relevant specifically to that project" does not.
in itself, preclude implementing reusable modules.  If
modularity and cohesion are emphasized, it is certainly
possible to construct modules (packages, subprograms, ...)
that, while they may not be able to be moved intact from one
application to another, would need very little to refit them
for a different application domain.  We must be flexible
enough in our definition of reusability to accommodate the
range of legal and procedural impedimenta.

If the mountain will not come to Mohammed ...   Let's start
finding ways to use what we have.  Let's get everyone up to
the level of the current software engineering technology. 
Let's quit generating excuses and start attacking the
problem.

                               Michael P. Meier
                              (My opinions are my own ...
                               standard disclaimer)

royer@savax.UUCP (tom royer) (03/16/87)

In article <8703141928.AA20877@ucbvax.Berkeley.EDU>, BENNETT@sp.unisys.COM writes:
> Having just read the two dissertations on reusability
> submitted by Mr. Berard, I find myself wondering about a
> couple of things.
> 
> First, it seems to me that the Cost-Plus-Fixed-Fee contract
> is not, in itself a barrier to the development and use of


CPFF contracts might, indeed, provide a vehicle for developing
reusable software, provided that the acquisiton agency (the DoD)
was willing to pay for improved reusability and reduced cost
for the next contract.

The tendency of government contractors to overrun software development
(and other) contracts has, however, inclined the DoD toward the
Firm Fixed Price contract (rightly or wrongly -- that's another
discussion) in which the contractor is locked to an estimated price
which must be the lowest of those submitted by the bidders.  In
this fixed cost environment, there is little incentive on the part of
a contractor program manager to invest the added cost or schedule
necessary to produce truly reusable software since the benefits
will be reaped by the guy with the next contract, not by him.  Furthermore,
the contractor itself has little to gain by encouraging its program
managers to build such systems unless and until the DoD makes reusability
and long-term life cycle cost a part of the proposal selection criteria.

hsd@uvacs.CS.VIRGINIA.EDU (Harry S. Delugach) (07/29/87)

Can someone tell me how to:

1. Access the Ada Software Repository ?
2. Get an index listing of its available files ?

I am assuming that normal Ada users (like myself) could make use of
public-domain re-usable software.

-- 
Harry S. Delugach   University of Virginia, Dept. of Computer Science
                    UUCP: ..!seismo!virginia!uvacs!hsd
                    INTERNET: hsd@cs.virginia.edu
                    BITNET: hsd2x@virginia