I like the way Niel Macehiter once summed up the value of ROI calculations, as it relates to SOA or any other IT project: it's a formula usually conjectured after the fact to justify expenditures.Cost-justifying SOA is like building a car, then trying to calculate the ROI of the nuts and bolts, rather than the completely assembled machine
So, while ROI can provide a rough picture of the value of a project, the relevance and accuracy of ROI is often suspect. For a murky concept such SOA, the math grows even fuzzier. The question Does SOA have an ROI? was posed asked in the latest edition of Datamation -- not to mention countless other articles, conference sessions, and podcasts.
Gartner analyst Randy Heffner says as much in a report quoted in the article: "Any attempt to assign a specific ROI to SOA should be viewed with heavy skepticism."
SOA needs to be viewed in a larger context, Heffner said: "Because you should not be selling SOA. You should be selling the solutions that you're building." An analogy would be building a car, then trying to calculate the ROI of the nuts and bolts of the car, rather than the completely assembled machine.
SOA is a set of best practices, a philosophy, and a drive toward business transformation. SOA, for the most part, is intangible, with long-term results to the business.
In many cases, SOA is a "strategic bet," Heffner says. But that's okay, because some oif the biggest business decisions made are more strategic bets than hard-dollar justifications. An example of such a strategic bet is Apple’s decision to invest in the iPod and iTunes. “There came a time when it was a strategic bet. Somebody could have all the data behind them, ‘We think this will sell this much or that.’ But at some point it’s just pure speculation. And they had to say, ‘Here you go – we’re going to do this.’”