Friday, October 26, 2007

SOA & BPM? Beware - two-tier solutions might be back...

Lately, I have been seeing a lot of wonderfull features of a BPM technology suite.
Point, click, ah, building applications is so easy. Point to existing web services, pull them in a BPMN flow, create Xforms that talk to web services, no pains!
Sure, it's easy to create the application, given the current requirements and services.
But what if a service change?

Suddenly I found myself back in early 90's, with 2 tier client server tooling. Oh, what a delight after the green screen software. Widgets, windows, and click click link it to a database table, an SQL query, and tada, the software worked!
Until a requirement changed, we needed to make a small change to the database, and realized 40% of our windows would not work and needed fixing (even though their functionality did not change...).

It's called coupling....

I am assuming that many of these BPM tools have this risk: the risk that we build BPMN and presentation layer stuff, directly connecting to services. Leading to heavy coupling.

The alternative is supported by most tools too, I hope: an intermediate layer, that shields presentation to back-end services. Call it controller or business objects or whatever -
but please use it...

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