It would seem that “Service Oriented Architecture” (SOA) is taking off as a technology in fashion. As usual, most of the news is generated by people wanting to sell it as the next big thing ready for the prime time. If followed as it is being sold at present, the concept is liable to lead to significant performance problems. SOA is sold on having a large number of “users” who are then often other systems. This is followed all the way back to the real users through an unknown number of tiers. The complexity of managing this sort of architecture increases significantly as the number of tiers increases. If this is then managed without due consideration for managing the system capacity and performance the result will be problems in the future. That is not to say that I don’t see a benefit in the overall technology – there is great potential. Just consider carefully how the performance of operational systems might be proven to be sufficient for the long term.