OK i get your point , but we can get the productivity rate for the activity as all not divide it to more than one activity
for example : RC Footing , we will get the productivity for it as an activity
we will not divide it to ( Shuttering work , steel Fixing work , Concrete Casting , Concrete Curing )
You can make it as the previous sub-activities and get the productivity for each one or only one activity and calculate its duration and any relevant resources
you can use the 2 methods and in this workshop we will not divide it