Not sure how it all started, when or why but WOA is getting a lot of press lately. Everyone has an opinion. For what it’s worth, here’s mine.
SOA is hard. We’re increasingly hearing about stalled or failed SOA efforts and proponents of WOA are seeing this as opportunity to get some air time. There are many discussions about the relationship between SOA and WOA, and there seems to be three schools of thought emerging. I don’t think any one of them hold up to scrutiny.
First School of Thought: WOA is a stepping stone to SOA.
Some organisations are a bit nervous about SOA and they want to dip a toe in the water. The right way of dipping a toe in the SOA water is to start small, do a pilot project and then deliver additional benefits iteratively. WOA is the wrong way of ‘dipping a toe’ in the water.
Successfully delivering a WOA solution is great – but you haven’t learned anything about SOA.
At the technical level you’ve learned nothing because the technology is different. For example, learning about REST teaches you nothing about developing SOA with WS-*.
At the business level you’ve learned nothing because WOA is all about technology, whereas SOA takes a broader view – it’s about the business – change management, politics, governance, business processes and the like. You can deliver WOA without having to deal with the ‘hard stuff’.
If WOA is all that you need to solve your particular business problem then go with it. Just don’t expect WOA to magically ‘scale up’ to full blown SOA – it’s not a stepping stone. It is a step – but a step in a different direction.
Second School of Thought: WOA is a fallback position for SOA.
Many organisations have started off down the SOA road. A business case was made, approvals given and cheques written. Everyone is excited about the possibilities. The only problem is: things aren’t going well. What now? Some people see WOA as a way to save face – a fall back position.
The problem with this is that SOA is expensive and it is disruptive. When you go to all the trouble and expense of SOA you’re expected to deliver real business results. If, instead, you deliver some WOA eye-candy then the business won’t be impressed. You cannot match SOA ROI through WOA. Sure, delivering something is better than delivering nothing – but WOA is not a credible fallback position for SOA.
Third School of Thought: WOA is a replacement for SOA.
SOA and WOA are two different solutions to different problems. They’re just tools. You need to pick the right tool for a problem. SOA is more complex, expensive and disruptive than WOA. If WOA solves your business problem then use it – there’s no point using a sledge hammer (SOA) to crack a nut. Conversely, if you need to transform an organisation or create rich solution then don’t try and do it with WOA as you’ll soon outstrip its capabilities. Neither one is a replacement for the other.
The Bottom Line
Any discussions about “SOA vs. WOA” are a complete waste of time. Apples and oranges. You can only compare the two at the technical level. But that’s not where the discussions and comparisons should be.
It is imperative that all architects keep their eye on WOA. But don’t get distracted. Nobody said SOA was going to be easy but if you began the journey for the right reasons it’ll be worth it. Stay the course.