RE: Development ideas -- MIDRANGE-L

> From: McBride, Catherine
>
>      We have an opportunity to rewrite an entire system using whatever
> platform we select.  It's currently mainframe based.  I have been
> asked what
> development languages and tools there are for the AS400.  We have
> an 820 and
> use RPG and COBOL already.  What this programming group seems to
> be looking
> for is object-oriented type stuff, though.  We're fairly new to the AS400
> world.  Is there GUI-based application development for the AS400?  What
> languages?  The programming staff would like to be able to
> develop and test
> quickly, and have a full complement of programming tools to work
> with.  The
> programmers who would be writing this system have VB and SQL server
> experience.  If any of you have suggestions for us, we'd be very
> appreciative.   Thanks much!

Wow!  What an opportunity!

There are a million questions that should probably be asked, but let me
preface this by saying that the iSeries (a/k/a the AS/400) can work and play
just fine in an SQL environment.  Many of the folks on this list are very
versed in using SQL, especially the wonders of stored procedures, to
efficiently interface between languages such as VB and the more
business-oriented languages such as RPG and COBOL.

Okay, on to a couple of your questions.  There is no native GUI for the
iSeries, although there is extensive support for browser-based UI.  Is your
application going to require a thick-client interface or a browser
interface?  If thick-client, are you a Windows shop or will you be using
non-Windows platforms at some time?

The reason I ask these question is because they will determine your choice
of UI development tools.  The fact that your developers are primarily VB
folks means they will be skewed towards Windows thick client interface, but
you need to be sure that this is what your end users need.  For example, a
thick-client interface may not be the best for Internet access.

And even if you do go with a thick client, I would suggest looking carefully
into an n-tier architecture, where there is little or no business logic on
the workstation.  Instead, the business logic (validating transactions,
updating the database, and so on) would be written in a traditional iSeries
language such as RPG, and the thick client would access these programs
either through stored procedures or through a more traditional client/server
protocol.

In this sort of tiered architecture, the iSeries is a powerful server.  It's
built in security and auditing features make it a great centralized data
repository.  Not only that, with a good n-tier design, you can support
different UIs based on your needs.  The same business logic servers can
support thick clients written in VB, Linux application written with Java,
and browser-based applications usnig servlets and JavaServer Pages.

Anyway, I just thought I'd chime in on some of the things that make an
iSeries a great server for an application such as this.

Joe