What Are Your Biggest Access Control Challenges?

I am curious to hear your feedback on what your biggest challenges are with access control systems. Depending on who you are: installer, manufacturer, end-user, designer, consultant - your challenges may be different, but that's the value in this discussion. For example, I expect some of the biggest challenges for installers are: 1) integrating systems with existing door hardware, and 2) navigating the health/safety codes Likewise, I'd guess big headaches for end-users come from: 1) Users losing credentials, or possessing improperly provisioned credentials 2) Random components breaking or not being properly maintained Am I wrong? Am I correct? Tell me, because I'd enjoy hearing your feedback. Be sure to include which type of user you are (designer/consultant/end-user/etc). Thanks!