Ultimately, when you're running an organization or a department, you have to be able to explain variances. You alluded to that in your comment and said that whenever there are variances, some kind of explanation should be mandatory.
Sometimes when it comes to explaining variances, there's some very evasive language. What are some specific things we can do to identify a variance and hold people to account, if there is a significant variance between what they planned to spend and what they did spend?