While constructing and evaluating the assembly outputs, access to the object inputs may be required; such as the structural member where the footing is to be placed. These inputs must be retrieved from the business object using the Occurrence property on the Custom Assembly:
'accessing the footing business object
Dim oFooting As Footing = DirectCast(Occurrence, Footing)
Direct casting of the occurrence to the specific business object provides access to the object-specific properties which would include the inputs (supported members and supporting members in the example above).