There are certain restrictions associated with the use of multi-level substructuring within FEMVIEW. Nodal co-ordinates, element topology, element sets, and material properties can not be entered under an assembly header (i.e. DIHED called with OPCODE = 3). These datasets can only be entered at the model level. All other datasets can be entered at either the model or assembly level, and if at the assembly level will refer to the assembly only.

Transformations entered at the model level may be used to locate the model in an assembly defined later. Transformations entered at the assembly level may be used to locate the assembly in a larger assembly defined later.

When results datasets are entered at the assembly level, they must be entered in the same order as the models were added to the assembly. Furthermore, it is not possible to omit sets of results from one model at this level, unless it is the last one. Failure to comply to these restrictions may result in the results and models becoming mixed up.