We never have the same key in two units in the same complex and we swap the key upon tenant turnover but our units have slow turn over. 

I worked at an apartment complex where we rented by the bedroom and it's very important to outline policies regarding the security deposit, shared common areas, damage charges, etc. 

At the apartment complex where I worked, we would hire painters, carpet cleaners, etc. on a large scale.

Mainly because of the apartment complexes (condos) right there.  

My partner and I focus solely on value add apartment complexes.

@Clifford Charles it's probably more complexity than you need starting out.

There is another system I installed into a small multifamily complex we purchased last year which was from True Submeter (disclaimer: I am now a sales rep for them because I think they are awesome!)

Contributors: Sam Webb 40-unit apartment complex in Houston, TX.

I live and invest in Indianapolis, Indiana, and I know larger apartment complexes are able to do this. 

I encourage clients to hire eviction services for routine cases and I take the more complex ones.Point of order: If you go to the property geared up for war, that's your ***.