A hierarchical enumerated list is a complex data type in which there is a collection of related enumerated lists and a value in a higher level list constrains the valid values in a lower level list. When a hierarchical enumerated list is used, a separate property is created for each level in the hierarchy.
Examples of hierarchical enumerated lists in Smart P&ID are Equipment Class, Equipment Subclass, Equipment Type, and Fluid System, Fluid Code. Examples in the SmartPlant schema include: EqType0, ... , EqType6, and ConstructionStatus, ConstructionStatus2.
When mapping between Smart P&ID and the SmartPlant schema, four cases must be considered.
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Simple enumerated list to simple enumerated list.
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Simple enumerated list to hierarchical enumerated list.
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Hierarchical enumerated list to simple enumerated list.
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Hierarchical enumerated list to hierarchical enumerated list. When mapping between two hierarchical enumerated lists, the number of levels in each hierarchy might not be the same.
EnumConversions
A special Property Conversion class is available to support publishing and retrieving of enumerated properties. This class is called EnumConversions, and it is used for all cases of mapping enumerated list properties.
Mapping Properties
Only the top level properties associated with a hierarchical enumerated list are mapped. The lower level properties are left unmapped. The EnumConversions object obtains all of the values from the set of related properties even though they are not explicitly mapped.
Tool Schema Relationships
The MapEnumList objects that form an enumerated hierarchy must be related to each other with the Constrains and Constrained By relationships. The EnumConversions object relies on these relationships to get the job done.
Mapping Enum Values
An enumerated value within an enumerated list hierarchy can be mapped to any value (at any level) in the target enumerated list hierarchy. There is no explicit relationship between the levels of two hierarchies.