This is the first in a series of blog posts where I discuss what I see wrong with SOA (Service Oriented Architecture) in the way that it's being sold by vendors. The first installment is about how the need for SOA arose: tactics vs. strategy.
No company starts out as an Enterprise, they all start as a company, with just a few employees. As such, their IT needs are small, handled by a small group of developers who can chat with each other over lunch about what's going on in the IT "department". As the business needs software, they have some process to get the requirements to the developers, and they write code. Thus, the accounting department comes to the developers and says "Here are our requirements for our new accounting application", and the developers build some version of it. Inside that application are some small parts of something that the entire company cares about, for example, some of the aspects of customers. Meanwhile, the marketing department comes to the developers and says "We need an application, and here are the requirements", and the developers build it. Of course, this application also encapsulates some aspects of a Customer (not the same as accounting, but possibly with some overlap). It is rare indeed that anyone looks around and tries to come up with a comprehensive strategy for application interoperability: you don't have time for that -- you're a small company, and if you don't get your software, you'll go out of business. This goes on for a while.
Then, one day, you wake up, and you're an Enterprise. The CIO looks around with dismay at all the actual entities the corporation cares about because they are scattered in bits and pieces in all these different siloed and packaged applications. And the database stuff is a mess, with shared tables and views and ETL jobs running on cron jobs. And the CIO throws up in his mouth, just a little. The CIO looks at the landscape, and realizes that the technical debt incurred over the last few years can only get worse from here, so he calls out "Help." Big software vendors are highly attuned to people in big companies (sorry, Enterprises) who can write checks saying "Help". They ride in with a solution wrapped around the SOA moniker. More about our friends the Enterprise vendors in a future part of the series.
What I'm concerned about in this post is the overall landscape, which is another way of asking "How did you get where you are now?" You got here because of 2 reasons: first, you took the path of least resistance when you were a company (before you became an Enterprise) because, if you had taken the time to build a comprehensive strategy, you'd have never survived as a company. Second, and more important, what is strategic to the business is always tactical to IT. Business people can go into a conference room and change the entire direction of the company in 2 hours. Or, the business may decide to merge with another company that has truly dysfunctional IT, but other business concerns override that. IT can never move as fast as the business, with means that IT always has to respond tactically to the decisions and initiatives brought forth from the business. No matter how much effort you put into a comprehensive, beautiful, well-designed enterprise architecture, it'll be blown out of the water the first time the business makes a decision unlike the ones that came before. The myth of SOA sold by the big vendors is that you can create this massively strategic cathedral of enterprise architecture, but it always falls down in the real world because the COO (and CEO) can override the CIO (and his sidekick, the CTO). If you can convince your organization to allow IT to set the strategy for what capabilities the business will have long-term, you should. However, your more agile competitors are going to eat your lunch while you build your cathedral.
Any enterprise strategy you implement must realize that you will always be in tactical mode in IT because the business strategy doesn't require physical labor. Any enterprise architecture you develop must allow the business to evolve according to it's wants (and needs). This is what my colleague Jim Webber calls "Guerrilla SOA" and what I call "Evolutionary SOA". More about the details ofp evolutionary SOA in upcoming installments.