Hi Laura,
We went live in January this year, and acceptance has been good by the teams who have used Workfront so far. We are starting in the IT group and spreading out from there, like treacle! Is the resistance coming for core-users like PMs, or Contributors, or Leaders? Because it may need a different technique for each.
Go do some interviews and find out what's bugging the users, there may be some simple fixes (usually it's a missing skill which can be fixed with a little coaching...). Leaders need to understand how the reports work in Workfront to get the best of them, contributors need to know how to personalise the Notifications, etc...
Some specific actions I have used..
A "Back-to-the-old-tool Day" - makes those dinosaur PMs realise that the old days were not what they remember
Update like a Pirate/Harry Potter/Sports Reporter/Monty Python Day - Make it fun! (Not a good idea if you have external vendors peeking in on your projects....)
We have started awarding little gold cups for significant Workfront project successes - silly, cheap, tacky, but people display them with a certain pride (and irony).
My leaders were really excited by the Worker Hours Weekly and Monthly reports we can create. (As usual, they were more excited by what has happened in the past month, than the risks of what may happen in the next month.....!).
Have a competition to see who can create the best report, or dashboard - You might discover a hidden talent in your team, or a report that everyone can use...
BTW - I'm a Brit, working in the US, so I may be infected with an enthusiasm which is counter to British cynicism when it comes to ideas like this....But, my point is, it may not be a need for reports which is the problem. Different people need different forms of reinforcement....
Cheers,
Phil