Overtaking a BMS has huge problems (I know, I am in that space). On one end you're talking about certified hardware for a variety of needs (hardware, especially

Overtaking a BMS has huge problems (I know, I am in that space). On one end you're talking about certified hardware for a variety of needs (hardware, especially certified to various ASHRAE/ANSI/etc specs is expensive for a small company, no two ways about it). Second is the "no one got fired for buying IBM" mentality - if you hook up with Siemens, JCI and the like, you have paid that huge maintenance contract to make the vendor fix their problem and you won't end up with an insolvent small vendor's VAV controllers which don't work.