Re: Ada & PDL (ick !)

[eachus@mitre-bedford.arpa (Robert I. Eachus)]

In article <1992Dec10.154343.24720@mksol.dseg.ti.com> strohm@mksol.dseg.ti.com 
(john r strohm) writes:

>  Which raises my old favorite question: As I understand it, the
>  output of the CODING phase of the project is compilable code, while
>  the input to the coding phase is the design of the (insert
>  buzzphrase of your choice here) to be coded.

>  Now we have PDL that is compilable and compiled and is the same lanugage as
>  the final implementation language for the project.

>  What I want to know is this:  How SPECIFICALLY does this differ from just
>  jumping straight into the coding?  I really wonder about this: I don't know
>  how to be certain in such a case that a real formal DESIGN was done, and
>  failure to do the DESIGN properly has killed or maimed a lot of projects.

     I'll take a shot at this...  COBOL many years ago tried to divide
the code from other parts of a program.  In some areas it succeeded
better than in others, but it did not try to split out design.  In Ada
the main division of compilation units in a project is into
specifications and bodies.  Detailed design is 90% concerned with the
package specificatations.  Coding is 90% concerned with package bodies
and subunits.  With a little bit of effort it is possible to have a
complete compilable design in Ada without writing a line of what would
be considered executable code in other languages.

     But...the problem that you mention does exist.  It is hard to
have a hard and fast rule as to what is design and what is coding, and
use this to keep people from riding off the deep end.  My attitude has
been that it is better to depend on good faith efforts by the
programming staff.  If their goals are yours, the project will
succeed, if they consistantly try to subvert the project, no standards
or rules will help.  The only case where you have to use judgement
with Ada is in determining when a "superprogrammer" is creating more
work than he is accomplishing, rather than flat out telling him to
stop coding or get off the project.



--

					Robert I. Eachus

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