Trying to find a good way to calculate Production rates

I hope this is the right subforum for this. I have a quandary that I think math can solve I'm just not sure where to start. I am trying to calculate the production rates of the construction of a building. It is a large hospital and there are hundreds of workers involved. There is a main schedule with activities. Each activity has a duration (planned and actual). If the activities contained all the same components then it would be easy to find the production. That is not the case. Lets take an example. Plumbing for the first floor might be a good example. There are multiple components in this activity. One is the piping. Thats got a length. Thats easy. Then there are elbows and T's and Y's etc. I could just brush over the fittings but then my calculations will not be accurate. It takes a lot longer to install a fitting then piping of the same length. So I am looking for a way to calculate the production of activates with variables. Maybe take the first month of quantities complete and have length as one variable and the amount of connections be other variables. So a 90 deg elbow would be two connections a coupling would be 2 connections, a Y' would be 3 connections and so fourth. Then compare the next months with this first months results. I am not sure exactly how to do this. If anyone can help I would greatly appreciate it. I have tried Goggling this subject but I keep getting economic results. Also just to let you know normally this is figured with man hours involved but I'm trying to get an alternate method without man hours. Just raw production rates. Another option would be to take the quantities of each of the different variables and figure it some how with the planned schedule. Then as components are completed somehow compare it to the planned duration. Thanks for any in-site you can give on this.