Relative asymmetry compares how deep the system is from a particular point with how deep or shallow it theoretically could be – the least depth existing when all spaces are directly connected to the original space, and the most when all spaces are arranged in a unilinear sequence away from the original space, i.e. every additional space in the system adds one more level of depth. This is a theoretical way of normalising total depth.
Relative asymmetry (RA)
Hillier, B. & Hanson, J. (1984), The Social Logic of Space, Cambridge University Press: Cambridge. pp.108-109