1. A method implemented in a computer system for constructing a database characterization of a stratified composite unit of elements of a functional system, the method comprising: generating and electronically storing a database system comprising a logical data model having a data structure representing an organization of parent nodes and child nodes for aggregating data entities and aggregating attributes of the data entities in a functional information system, the data entities representing elements of the functional system as a network of heterogeneous components, the data entities further corresponding to elements of the functional system ordered by their functional roles in a process converting inputs to outputs; electronically storing a set of data entities in the database system, the data entities corresponding to elements of the functional system; electronically assigning the data entity corresponding to an element one or more functional attributes, each of the attributes represented as an electronic tag, wherein the functional attributes characterize the roles of the elements in a process of converting inputs to outputs as represented in the logical data model; selecting multiple data entities, that correspond to respective multiple elements, for inclusion in a stratified composite unit; stratifying the multiple data entities that correspond to multiple elements into two or more groups based on the electronic tags representing the functional attributes associated with the corresponding elements, wherein the first group shares a first common functional attribute, and the second group shares a second common functional attribute; electronically accessing the database representation of the stratified groups; electronically iterating through the accessed representation to compute weights for one or more of the data entities corresponding to elements based on one or more of the stratified groups; and assigning the weights to one or more of the data entities corresponding to the elements included in the stratified composite unit, wherein the assigned weight is based on the relative location of the data entities in the logical data model and the weights are calculated such that the sum of weights of data entities in child nodes below a parent node equals the weight of the data entity of a parent node; electronically storing the assigned weightings in association with segmented groups in the database system; and receiving and storing an update to a data entity in the database system that corresponds to a change in the functional system, the update based on a process converting inputs to outputs as represented in the logical data model.