1. A method for modeling a system having one or more components, comprising: (a) dividing said system into one or more components; (b) defining a plurality of realms, wherein each of said realms contains objects representing attributes and relationships of selected ones of said one or more components, wherein said one or more components represented include at least one physical element of the system; wherein each of said plurality of realms contains at least one object common to at least two of said plurality of realms; (c) defining associations between said plurality of realms to unify objects in said plurality of realms, wherein said associations represent an identification of said at least one object common to at least two of said plurality of realms; (d) unifying objects in said realms based on said associations that said at least one object is common to at least two of said plurality of realms; and (e) processing a function in a first realm of said plurality of realms independent of said other realms of said plurality of realms (f) propagating a behavior, based on a result of said function, of one of the unified objects of said first realm to said unified object of a second realm of said plurality of realms using said at least one association between the first realm and the second realm to determine the impact of the function of the first realm in the second realm.