Should you change the product name?
Names are the hooks we hang ideas on.—Al Ries and Jack Trout, authors, pioneers of positioning theory.
The research is in. The old product name is out; we have a new, super-duper product name. We've got all new branding. Now, how in the world do you get buy-in from the rest of the company?
Changing a project code name to a marketing brand name is nontrivial. That's why I always recommend that project names be offensive or embarrassing in some way so that developers don't fall in love with the project name. Had you called the project "Spaghetti" they probably wouldn't fight the change so hard.
It's perhaps even harder to change names after an acquisition. I don't know the details but I imagine Sage had major problems when they renamed Timberline to Sage 300 Construction and Real Estate (or Sage 300/CRE). I know they still have a Timberline User Group which refuses to change its name. I bet the developers continue to refer to it by its "real" name and not by the marketing brand name.
And for what it's worth, one of my clients estimates the cost of a name change to be $1,000,000 -- they're constantly finding areas where the name was hard-coded.
It's helpful to think of it this way: the developers have named their "child." Would you change your child's name because somebody in marketing said that "Brittany" isn't as popular now as "Emma." To sell it, you'll likely need to socialize research that proves that the new name is a vast improvement.
Everyone who deals with customers must use the marketing brand name.When changing a name, worry primarily about internal language--the support team and anyone dealing with customers must use the marketing brand name instead of the unofficial project name. The server names and even URLs are probably irrelevant to customers but all other visual elements must be changed.
Any internal resistance may be the result of a lack of support at the leadership level. Basically, it should be "change the name or you're fired." But that only works if the leadership is truly on board.
Make sure you have a name that people can pronounce, can remember, and can type without confusion.
Names matter. After all, you named your kid(s), didn't you?