The SOA thing as I would explain to my mother

Take SAP SCM tool as an example. To be able to do transportation planning the addresses of customers, vendors and plants need to be defined in geographical coordinates, so that it becomes possible to define and optimize the distance between places. This task of finding the latitude and longitude from the address data is called geocoding.

With SCM comes a plug-in software that one can install to do the geocoding. Of course this is not a very powerful tool, it comes with a limited database of addresses and just for some countries. This is the traditional architecture, the software has some plug-in that solves a particular need.

But with some little work one can plug the SCM to use the geocoding web service provided by Yahoo or Google. That way one can get very good geocoding without the burden of having to buy, install and update a large geocoding address database. This is the SOA architecture. The software uses a stand-alone webservice internal or external to the company.

The Lego Analogy

Very interesting this post about the use of the Lego analogy when presenting enterprise software. The Lego analogy is an old pal. I remember it in Visual Basic, then I remember seeing it in Zope talks. I never saw it in SOA, but then, I don't pay a lot of attention to the SOA thing.

I also think Lego is a bad analogy for enterprise software. From my experience with computers, the closest to the Lego would be a scripting language with a large object oriented library. One can just start assembling a bunch of pieces, no previous design needed, and in a reasonable amount of time get the wanted result.

When I think of SOA I usually think more of something in the line of the Garderna system. In most of these accessories water is meant to flow, so hoses of different dimensions are needed to connect the pieces. Since all pieces connect using the same standard, it becomes really easy to plug and unplug equipments to the hoses.






But people are not expected to build the equipments, each piece is already a fully working product. People just have to think what are the pieces they need for their garden (or they start by buying the basic and then add more when budget allows).






And of course, like models, all analogies are wrong, but some may be useful.