The RAD paradigm becomes more, not less, important as we move from two-to three-tier development. Scott Hebner, IBM Software
THE SLOW BOAT TO THREE TIER
When it comes to moving business logic to a middle
tier, there are some things RAD can't hasten.
Vendors are rushing to ship RAD tools that simplify
multitier development, but some integrators are quite willing to wait. "The
Web's success is forcing a paradigm shift that's taking us and our customers
toward three tier," says Howard Block, technical director at Per-Se Technologies,
a large integrator based in Atlanta. "But that doesn't mean two-tier client/server
work is going away anytime soon."
"The Web's success is forcing a
paradigm shift that's taking us and our customers toward three tier."Howard
Block, Per-Se Technologies
Certainly not with customers such as Bowne & Co.,
for instance,one of the world's largest financial printers. Bowne distributes
a huge amount of electronic documentation via the Internet and wants to move
toward a three-tier environment to perform that work better, Block reports.
"Right now their databases are running on VAX systems,"
he says. "They want to migrate those databases to NT, partly because of
the new development tools available for Windows. But it's not the sort
of thing you do overnight."
Handling The Business-Logic Move
Much of the work Per-Se has done for Bowne so
far has been with Sybase's PowerBuilder. lt has proved to be a
good development environment that offers a ready pool of programmers Block
can hire to get the job done.
Bowne's existing business logic was built for
a two-tier client/server world. Sybase's forthcoming tools will let Per-Se
move the business logic to a three-tier environment without having to
scrap all the legacy code. Too bad neither vendor nor customer is ready
"The architecture behind PowerBuilder has long
supported the separation of business logic and GUI in preparation for
three-tier architecture. All of our PowerBuilder development efforts involve
this separation. PowerSoft is finally starting to provide tools that art
able to move this business logic to other tiers," he observes.
"Working in a two-tier model makes sense for many
of our clients today. When it comes time to move that logic to a middle
tier, I'm confident that the tool will be able to handle the move."