This is a text description of modelhie.gif, which presents the hierarchical structure of the Model interface and the classes that implement it. The Model interface is implemented by the MdmModel class and the CustomModel class. The MdmModel class has the following subclasses: MdmDimensionCalculationModel and MdmDimensionedObjectModel. The MdmDimensionedObjectModel has the following subclasses: MdmAttributeModel and MdmMeasureModel.