Resources are typically grouped with other resources, in a resource hierarchy. For example, one plant could have several work centers, each of which could have several skills defined as being necessary for that work center. However, the types of resources that can be assigned to another resource are contingent upon the types of resources involved, and the categories of each resource. For example, a work line can have a resource pool assigned to it (Y), but cannot have a plant assigned to it (N).

The following table shows where resources can be assigned within a resource hierarchy.