The 80:20 rule for SOA
There is a really good post from ZDNet suggests that the 80:20 rule of software development needs to be changed for SOA (Services Oriented Architecture).
Here’s a snippet from the article.
Then, over time, with investment, the balance shifts toward the 50-50 point, and reuse forms a majority of a composite applications or business process, even for highly specialized applications. These composited functions then become business-focused service frameworks, to then be reused and adjusted. Those architects that gain experience within business niches and verticals to create such frameworks can make significant reuse of the services.