The Gartner 2008 SOA User Survey is a good read with some surprising insights into SOA adoption.
One interesting development is that the rate of SOA adoption has slowed in 2008. About half of respondents last year who were planning SOA adoption, now have no plans for SOA adoption. The two main reasons for not pursuing SOA are a lack of SOA expertise, and the perceived lack of a business case. These reasons may be correlated in the sense that lack of SOA expertise makes it difficult to build an SOA business case. But the fundamental conclusion is that SOA doesn’t make sense for everybody.
SOA Adoption shows considerable geographic disparity. Europe has almost universal adoption (70% currently using), followed by North America (55% currently using) then Asia (25% currently using). The majority of organizations in Asia have no plans to adopt SOA. The report doesn’t really analyse why Asia has such low SOA adoption. My guess would be a combination of factors including lack of SOA expertise in the region, the characteristics of Asian companies being late technology adopters and the preponderance of manufacturing in the region which the survey shows has overall low SOA adoption compared with other sectors.
Organisation size correlates strongly with SOA adoption and the range of SOA deployment. There is a sweet spot for mid-size companies with current SOA adoption high in companies with employees between 1000 and 10,000. Large companies obviously struggle with the governance processes required to adopt SOA enterprise wide.
A big surprise for me was the correlation between SOA adoption and primary development language. Forty percent of current SOA adopters use Microsoft .NET. There is also a clear trend over the last 3 years away from Java toward Microsoft .NET and “other” languages such as dynamic languages. Correlation doesn’t mean causality so there is a lot of wiggle room in how you interpret this but clearly there is a move away from Java for SOA development. Harkening back to the COM/CORBA wars of the 90’s one of the key factors was that the Microsoft development environment made COM so easy to develop versus the complexities and diversities of CORBA that eventually COM came to dominate the component world. Is history repeating itself?
Web Services are the dominant SOA model, but a significant minority uses POX and REST approaches. About one third of existing SOA adopters already use or are planning to adopt EDA. The report also claims significant plans for WOA adoption, but I’m not convinced by the data. An eyeball comparison between Figure 14 (current WOA adoption) and Figure 15 (planned WOA adoption) doesn’t show a great deal of difference to me, except for Figure 15 looking a little more “peaky” around the 50% mark. So WOA adoption will increase, but I’m not convinced the data shows this is “dramatic” as stated in the key findings of the report.