Design enterprise staging area for two different organizations. First organization went through number of iterations, tools, platforms. It started out as grass roots agreement between several architects on different projects and grew into enterprise data warehouse solution. Second organization was also grass roots started by just myself as POC then growing interest small step at a time until the staging area (sometimes referred to as an ODS but I would disagree on that term) became the sole location of archived operational data purged from operational applications and the central hub for marketing operations besides being the central source for analytical information. In the first situation the staging and EDW were updated daily. In the second situation, the entire lifecycle (staging and integration to EDW) updates hourly.
More effective deliverable milestone expectation management.
I believe there is the false impression of control that project management assumes when in fact often big enterprise efforts often seem to grow organically rather than the assumed ability to intentionally revolutionize and organization. If technology and skill sets are adequate (foundational requirements) then the real challenge is people and obtaining an executive champion who will sell the concept. That takes a very special skill set in dealing with people and knowing the organizational culture. And it takes time. In the first situation, too much money and people were thrown at the problem and the irony was we had better efficiency and product quality when it was just a few folks involved who operated well as a team. The overhead of large numbers of consultants and competing consulting firms when it got a lot of momentum resulted in large amounts of waste and analysis paralysis.