OK Blue light time is time the arc is flashing for the most part.
What we did was first we didn't let the guys know we we're doing a time study we were running at about 1/4 capacity 3 fitters 4 welders we time studied everything that goes into producing a spool/spools.
We timed it from the time the fitters would pull pipe off the pile fly across the floor with the bridge crane load the saw or beveling bed which ever you are using cut it prep it, fit it tack it and weld it out fly it to the truck or floor where ever your laying it down and we took an average of the amount of time and divided it by the diameter inches. (Piss Breaks, BSing you can't catch every minute of non productive time, phone calls, hangovers etc)
There are a lot of things that go into this amount of roll welds vs 1/4 welds flipping big spools etc so we rate the spools. a piece of pipe with two flanges on each end would rate a 1 and a piece of pipe you have to 1/4 a lot and one that has a lot of thread-o-lets would rate a 3.
Thats the way to do it, asking a welder what he thinks can be dangerous I found out the hard way when we asked one of our more cocky welders what he thought and we were way light. This guy forgot you need to take brakes take an occasional phone call and take a dump every now and again etc etc.
This study is subjective as you get into bigger crews production can go down so watch out for that. Anyway schedule 40 MIG process we are getting about 9" to 10" per hour, Note this was the 1/4 of capacity so my most productive welders and fitters are in this mix
For the two pass tig root and 7018 fill out about 3" per hour. Be careful! with how much efficiency you want to give away to the customer. Got to go 2bcontinued