Big programs of work tend to be comprised of several small IT projects stitched together. Business architecture makes sense that way - build and release in small doses and keep building. Momentum - in both IT roadmap and business outcomes - is great and demonstrable in this way. Theoretically, Everything goes smooth and the program is complete and every one is happy. However, in reality, things never go as per plan. No plan survives the impact when the rubber meets the road.