Business managers who think about IT tend to think about it in terms of large projects.
This is probably a normal state of affairs: the original systems they asked for were built that way, and the packages that replaced them were likewise massive efforts.
What this has done is create a worldview where making change depends on obliterating what went before: the analogy would be needing to tear down what exists in order to build a new building complex, every time.
In this third age of IT, the one which services are emerging in, the game changes.
The whole idea of service oriented architecture is that individual services can be on their own reinvestment cycles, adding value to each “application” that makes use of the service as soon as the change is made.
The changes, in turn, are small in scale, and easy to carry out.
It’s a very reasonable idea, but far too many companies are failing to really get going on it because the job of starting seems so massive.
There are some, though, that have a different attitude. Their idea is that some of the initial services are used simply to link things together.
Minor maintenance — or simply bypassing existing code in part of an existing system — is sufficient to get the job done.
Slowly a web of services begins to emerge. Eventually some of the larger structures will need to be dismantled and replaced, but by then most of their function has been subsumed, lowering the risk, cost and scale of doing so.
What these IT groups are doing differently is recognizing that the lifespan of a service is far shorter than the code it replaces or adds onto.
As a result, they are able and willing to do something rather than wait to get it all “perfect”, and then try to justify a massive reinvestment.
By focusing on cleaning up rough edges, operational trouble-spots, or adding value around the existing portfolio, they are willing to trade off a little increased complexity at first to make progress.
By demonstrating a growing mastery of reuse of the services, quality of construction, and rapid delivery, they build business confidence in continuing the process.
Unlike the architecture of real buildings on city streets, IT systems can have inter-system bridges crossing on many levels to solve different problems. These can be widened, branched, etc. as needed without shutting the complex down.
“There is no perfection; there is only progress.” To gain the support for the service oriented architectural transition, deliver value early and often.
Be prepared, therefore, to add it where you can — and be prepared to walk away from the bits that are no longer needed as you go.