One tip is to be creative and remember to use many different vehicles for communications and training. People consume change differently. You can find some more ideas and templates in our Change Management Activities Guide to help you plan your roll out.
Some tips that I can make are...
1. Employees like gifts. Give them something to remember the training event. Perhaps a pen with the project logo or credit card holder or a pouch to keep their receipts. You need not spend too much on it.
2. Make help easy to access. Communicate links to access training material, names of super users and administrators. Perhaps even intranet forums where employees can help each other and modes to make suggestions. Conduct refresher training for new joiners and those that wish to revise their knowledge.
3. Publish results of groups of employees (like departments). There is nothing like competition to foster adoption.
I tried to find a way to make a contest out of it (Executive vs Marketing etc.) but had a hard time figuring out what the measure of success would be and how to track it. Is it the expense report with the fewes errors, or the team that submits theirs correctly the fastest? I really wanted to do this but there were so many "what ifs"...
I find it odd that there would be an option open to employees on where to file expenses. Or that it needs to be "fun".
When we set up Concur - employees were required to use Concur for expense.
We require all employees to use Concur. However as mentioned, no one likes to do expenses so I try to make it as painless as possible through patience and kindness. As another user noted, in our training sessions, I give out lego minifigures to those who were paying attention and can correctly answer questions. I also made a user guide that has "easter eggs" or lighthearted jokes as a reward for those who actually read the guide. Most importantly, there is a dedicated in-house employee to answer any questions or help a user that gets stuck. We are a smaller business so communicating with each individual user when I see they are struggling is pretty easy for us.
As an avid fan of the MCU I love the easter egg idea! Sounds like your people are in good hands.