I maintain an in-house developed 'enterprise database app'. When someone suggests new additions to this app, I tell him/her to use Excel to test their idea for

I maintain an in-house developed 'enterprise database app'. When someone suggests new additions to this app, I tell him/her to use Excel to test their idea for a few weeks first, and then ask again. This gives a pretty good idea what they really want, because if people have to track stuff themselves they'll do only the barest minimum, and that's eventually what should go into the enterprise application.