You control who can enter and gain entry by person, area, day of week, time of day, etc….
More Secure Advantages over keyed locks.
No need to re-key locks employees leave. Employees can duplicate keys but not access cards.
No way to track a metal key, but you can track access cards.
Discourage Inappropriate behavior.
You can account for who opened the door and when.
One card does it all.
No need to carry multiple keys.