Locks and key management, lockout and doorbells

[Account Closed]

I have few multi family units and management of the keys and locks have been a nightmare.  Changing locks every time tenants move out to broken locks.  Then i had to resolve multiple lockouts this year, wasting 4 hours commute (I couldn’t say go get a locksmith)  What solutions have worked for you?  I looked into digital locks and the cost is very high when you have two doors per apartment.

Doorbells - with the old houses the wiring is old and frail.  The wireless solution is not working well - batteries dying too often and complains that the bells just don’t work.  And In Multi family house, that many doors bells at main building door seems messy.  

Any good solutions or deals/packages you purchase to help with those nuances?  Love to hear solution and cost.