By using node types and their properties, you can establish the hierarchy of a project work breakdown structure (WBS) with units, areas, line numbers, and isometrics. Node types are distinguished by the properties assigned to them. You can to assign the same properties for structures of the same node type but only one node type can be assigned to each node in the WBS. Also, a property can only be allocated once to a node type. When allocating properties to a node type, the user gives sequence numbers which establishes the sequence of variable node properties in the WBS.
Node types or node type properties can only be deleted if the node type has not yet been allocated to any node within the WBS.