This model supplements the information of EngineeringUnit Properties, providing comprehensive ObjectTypes for quantities and units and their linkage. See 5.6.3 how EngineeringUnit Properties reference instances of these ObjectTypes. It is also possible to specify AlternativeUnits and the conversion factors.
Furthermore, the model provides a powerful way to relate quantities and units to established works of other organizations (see Syntax References in 6.3).
Figure 6 Illustrates the model.