Do you consider your maintenance vendors to be partners? Or are they merely vendors by default? Perhaps only their existence and good fortune to be located in the right place at the right time was enough for you to give them the nod, and you’ve been relying on them ever since?
How many times have you spoken to them in the past six months (a call or visit that wasn’t precipitated by a complaint or incident)? How many times have they asked how they’re doing? Do they even know how you rate their performance? (assuming you do in the first place) How much have they invested in the relationship over the last year?