Given two system structure functions F and G, the authors consider the assemblage of n copies of eac of m components in two ways. One way is to assemble single copies of each of the m components into n systems with structure function F, and then assemble the n resulting systems into a supersystem with structure function G. The other way is to assemble the n copies of each component into a supercomponent with structure function G, and then assemble the m supercomponents into a system with structure function F. Denote the structure functions of the supersystem by Gℝoslash;F and of the systemwith supercomponents by Fℝoslash;G, respectively. The authors compare the two assemblages for structure-wise superiority. When G is the parallel structure, then Fℝoslash;G is always better than Gℝoslash;G, this is the well known engineering principle that component level redundancy is better than system level redundancy. In this paper the authors consider general structure functions F and G, and give necessary and sufficient conditions that Fℝoslash;G and Gℝoslash;F are structurewise comparable.
