<P> The theoretical foundations are summarized by Thermodynamics . When biological systems are modeled as physical systems, in its most general abstraction, they are thermodynamic open systems that exhibit self - organised behavior, and the set / subset relations between dissipative structures can be characterized in an hierarchy . </P> <P> Within most CGI and computer animation programs is the use of hierarchies . On a 3D model of a human, the chest is a parent of the upper left arm, which is a parent of the lower left arm, which is a parent of the hand . This is used in modeling and animation of almost everything built as a 3D digital model . </P> <P> Many grammatical theories, such as phrase - structure grammar, involve hierarchy . </P> <P> Direct--inverse languages such as Cree and Mapudungun distinguish subject and object on verbs not by different subject and object markers, but via a hierarchy of persons . </P>

The three principle levels within a business organization hierarchy are