[kgeist]

Wow, we had the exact same situation. We had a 15 year old CRM/ERP developed in-house, full of very specific and complex business processes/rules/entities tailored to how our business works. At some point, someone decided to migrate to Dynamics CRM. As it wasn't realistic to migrate immediately, they chose to do it incrementally: the both CRMs would be active at the same time, and there would be lots of data synchronizations between them, and our managers/the system's users would learn how to use Dynamics CRM in the meantime. The project was scrapped after 1 year because they realized that fully migrating it would took many years, and the managers didn't like the new CRM because it was lacking functionality (didn't match the existing workflows), and overall the whole synchronization stuff was pretty fragile and full of bugs. Now we've chosen the path of improving dev practices in the existing CRM to impove its reliability instead of hoping that somehow magically a new CRM would solve all our problems without any effort.