Note that a Grid Layout would be especially useful for rooms with raised floors where cabinets are installed in floor tile positions, card positions in a subrack, or subrack positions in a rack with rack unit connection points.<br/>Note that we allow for both Physical Resources and Physical Resource Specifications to have representations. It would be expected that only unique physical resources (e.g. buildings) would need individual representations. <br/>Note that in figure 11, we don’t enforce the concepts of holders and housings in the static model. This is because the concepts are dependent on the status of the static resource. For instance, it may appear that a card can only exist in a card position (in a sub-rack etc.). This may be correct for a card with a status of “installed”, but if the status is “spare” then it may exist in a store or if the status is “faulty-returned” then it may exist at a manufacturer’s repair center.<br/>