Is this really a process rationalisation project? Of course, there is often no real reason for the different processes. They just grew that way. In this case, rationalising processes makes a lot of sense.
However, many organisations try to use technical consolidation to force business process rationalisation. This is a risky strategy. Change management is hard enough at the best of times. When management attention is focused on technology, it is hard to engage the right players and easy to overlook key factors. If process rationalisation is the real issue, it is best to face it head on.
Sometimes technology projects are just excuses to address more systemic issues. That or getting some sexy new technology is used as a bribe for getting people to change the way they do things.
Graham also makes the point that consolidation frequently has the side effect of making the whole organization move at the pace of the smallest business group. I would go further and say that having every division on the same CMS slows the pace of innovation and enhancement to a pace that is slower than the slowest business group. A single system that serves everyone has so many dependencies (both functional and political) that it is nearly impossible to get anything done.
I think the market has largely accepted that having one CMS to manage everything is a pipe dream. I think that Graham makes the points especially eloquently. So if you need to talk someone out of a major consolidation strategy, please use Graham's arguments. Then try to achieve the same goals with targeted tools, better integration and improved processes.
Hat tip to the CM Pros Benelux for pointing the article out.