During execution of a program, the speed slider will sometimes display a number in brackets next to the percentage that you have the speed slider set to. This number is a scaled down value and represents the actual percentage that the arm is moving at. The speed can be scaled down for a number of different reasons: if a particular joint is being told to exceed its safety limits during a motion, if a joint move would result in the TCP exceeding its safety limits, if the elbow would exceed its safety limits, etc. The controller will automatically reduce the entire motion to keep the one value of concern below its threshold.
My question is this: is there a way to see what the cause of the speed scaling is at any given point in the program? I’d like to figure out what the bottleneck in a program is.
I don’t know of any “direct” way to tell which safety parameter is limiting the speed.
You could, however, isolate the parameter by raising each parameter one by one and seeing, if it makes a difference? 
Wouldn’t take too long.