When tackling the problem of how to dimension a central office, a street cabinet, a server room, etc., one is repetitively having the same discussions and making very comparable calculations. For instance a street cabinet of a telecom operator contains one small rack and one or two power blocks in there. It contains at max 3 (sometimes 4) shelves and each of those shelves can be equipped with a predefined amount of line cards. Finally this amount of line cards will be directly correlated to the amount of customers to serve via this street cabinet. Calculations of the dimensioning are as such clearly hierarchical in nature. For instance the amount of shelves will depend on the amount of line cards which is in turn dependent on the amount of customers to connect.
ECMN details the modeling and calculation in the process of dimensioning the equipment.