What's the best way to introduce the concept of using a single source for building maintenance in a industry that usually uses 3-4 different companies?

Walter: Tough sell if you are dealing with mid-20th century purchasing troglodytes. They tend to be slow, if at all, learners, whose usual response is to turn the crank even tighter under stress. Maybe stern words forma 21st-century practitioner could help (a self-serving thought, I confess). Or a case example from a respected company. I'm not sure that social media approaches would resonate with folks who don't get the difference between strategic and tactical sourcing and procurement. I can only begin to speculate about how messy supplier relationships get with uninformed, unaware, and unprepared procurement organizations. That is, if they don't know how to handle something as simple as maintenance, how much opportunity are they squandering on the mission-critical parts, products, materials, and services?

Thanks Art.