What is response ratio?
HRRN that is Highest Response Ratio Next scheduling is a non-preemptive discipline, as same to Shortest Job First (SJF) wherein the priority of all jobs is dependent upon its estimated run time, and also the amount of time this has spent waiting. Jobs gain higher priority the longer they wait that prevents indefinite postponement. Actually, the jobs which have spent a long time waiting compete against those that are estimated to have short run times.
Priority = (waiting time + estimating time)/estimated run time = 1 + (waiting time/estimated run time)