Thinking of setting the Project Department field to Multi-Value in Project Server 2010? You might want to rethink that. Or, at least make sure you won’t want to change it in the future… because, well, you can’t. It cannot be undone. Forgetting this little fact can have a big impact on your environment, especially if you’d like to use the Department fields in a cube. Can’t be done if it is multi-value. Some lessons we just have to learn the hard way.