The hierarchy of control is - as I've been informed by a professor who has been involved in safety research for the last 35+ years - one of the few safety models that has actually, demonstrably, improved safety. In short, it simply states that actions taken to control risk are more effective at the top of the hierarchy than those at the bottom. It doesn't mean that actions should not be taken at the bottom of the hierarchy, just that those at the top should be considered fir