An indicator to whether the whole assembly that is modeled is fit into the SAS data
     or if only a subset of the structural assembly is fit into the data.
     This data item is a pointer to _ihm_struct_assembly.id in the
     IHM_STRUCT_ASSEMBLY category. The IHM_STRUCT_ASSEMBLY category provides the
     details regarding the different structural assemblies used in the modeling.
     The default value for this data item is "1" indicating that the entire assembly
     being modeled is fit into the SAS data.