Creating NC Code Hierarchy 
An NC code hierarchy shows the relationship among the NC codes that operators have logged in the system. The system displays this hierarchy graphically in the Failure Data area of the nonconformance client in the POD.
You create a hierarchy among your NC codes by making them either primary or secondary codes and associating them with each other. You determine the place of an NC code in the hierarchy on its category and the level of granularity you want. A two- or three-level NC hierarchy is most typical when you use the PCA Dashboard.
Primary and Secondary NC Codes
You create an NC hierarchy by defining primary and secondary NC codes in NC Code Maintenance.
A primary code is an NC code with a category of failure and it is at the top level of a hierarchy and can have other codes underneath it.
A secondary NC code is an NC code whose category is either defect or repair, and it can be logged at any level other than the top level of failure.