The role class “Unit” should be used for linked chained production plants. It is used for hierarchization. The definition of a “Unit” is given in IEC 62264-1:2013, 5.3.8: “Process cells and units are the lowest level of equipment for batch manufacturing processes. Units are usually only identified if there is flexibility in the routing of product within a process cell. The definitions for process cells and units are contained in the IEC 61512-1 standard. The major processing capability or family of products produced often identifies the process cell. Examples of process cell identifications are ‘Mixing Line #5’ and ‘Detergent Line 13’. Process cells and units have well-defined manufacturing capabilities and batch capacities.”

The Unit is formally defined in Table 97.

Table 97 - Unit Definition

Attribute	Value
BrowseName	Unit
IsAbstract	False
References	NodeClass	BrowseName	DataType	TypeDefinition	ModellingRule
Inherit the components of the ResourceStructure
HasProperty	Variable	ID	BaseDataType	PropertyType	Optional
HasProperty	Variable	Version	BaseDataType	PropertyType	Optional