Here I list the three common SOA project delivery strategies.

common SOA project delivery strategies

1. top-down: inventory analysis (service inventory blueprint) prior to physical design (more up-front analysis), development and delivery, with a more strategic focus
2. bottom-up: immediate fulfillment of business requirements has priority without a service inventory blueprint
3. meet-in-the-middle (or agile)

Normally an extend of top-down delivery is usually required, as the service inventory and the required services have to be analyzed. This saves resources later on (lower governance than bottom-up).