Enterprise Application Architecture

Where I work we have a web application server that runs numerous business applications which are all connected back to a database server. Each application has it's own database and also shares read access to a database containing central data such as personnel and department information. The system, which I inherited, works pretty well, but it's architecture seems to be somewhat dated. As a part of my continuous improvements, I intend to start reshaping it.

With the current architecture, each web application manages all data access that it needs. Even access to the central data is managed by the specific application. There are some libraries that we have in place to ease the management of this, but the situation can still get difficult when we have to change the format of data in our central repository. Up to this point we have not had any data in the central database that could not be shared amongst all applications, but at some point in the future this may be necessary and would be hard to manage under the current situation.

It would be nice to move to a more service oriented architecture (SOA) approach in general, but the current economic conditions have put a damper on innovative solutions that could be costly or are even perceived as being potentially costly. So, I have been contemplating taking just the intranet systems that I am responsible for and implementing a web services based SOA approach.

It seems that this approach would be fairly easy to implement with each incremental improvement we do to the systems. First, we would write a web service provider, or a web application that serves no other purpose than accessing the central data. This application would then be responsible for controlling access to the central data. Then, as we make improvements to the existing applications we remove the portions of code that allow for direct access to our central data and replace it with calls to the new web service. The applications will still store the data (data keys) back to their respective databases, just the selection lists and details will come from the central data web service.
Published: 2009-03-07