flow-on effect - is something that happens as a result of something else. In your sentence, ambulance ramping (which I assume means the installation of good ramps at hospital emergency room entrances used by ambulances) is the first activity. By following good ambulance ramping protocols there is a flow-on effect, in other words a benefit, to paramedics' response times (the second activity that is impacted by the first activity). So, the sentence can be rewritten "Mr. Cook said ambulance ramping conditions have an impact on the speed with which paramedics can respond to emergencies." In my view, it is a bit of a strange term.