Re: Application design & architecture -- MIDRANGE-L

Bill,

Yes - intent is key. Which is going to be different for every company, andevery suite of applications. And, it will be different when new applicationsare added to the mix. A great SOArchitecture would allow flexibility tocater for these.

As for rules, business rules are often in our application code. Somedevelopment tools - Lansa, for example - have a repository of businessrules. So, file vs. program would be dictated by the tool you wish to use.Here is an interesting example of a company that thinks applications can bebuilt without code: http://www.sdtimes.com/article/story-20060501-06.html .I wonder where the rules are?


Trevor

----- Original Message -----From: "Bill Meecham"

Subject: Re: Application design & architecture

Trevor,

Thanks!
I think you're saying that decisions regarding granularity can be donebasedon system intent. I support a wide variety of dissimilar systems thathave
intersecting data requirements.  Those intersections change so the
temptation is to make the components as grainy as possible but then youhave
a potential performance issue.  It's a balancing act that usually gets
determined by the urgency of the request...unfortunately.

Eventually there are patterns that you see in building components that
become a guideline but there are always those stinking exceptions....of
course with smaller, more distributed pieces to worry about the newconcern
is the impact you'll have over the system instead of on a particular
program...but that's because global rule changes can be made once insteadof
potentially hundreds of times.
The next question is if those rules belong in files or programs. I usedto
think files but finally, after arguing for them
http://c2.com/cgi/wiki?WelcomeVisitors
<http://c2.com/cgi/wiki?WelcomeVisitors> , I think that too depends on the
application.

(time to head home)
bill