Work center hierarchy 
Work centers can be grouped into a work center hierarchy . Apart from the top of the hierarchy - the hierarchy root - every work center in the hierarchy is subordinate to another work center.
One work center can exist in several work center hierarchies.
A work center hierarchy can include several plants.
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Work center hierarchy
Use of Work Center Hierarchies
Work center hierarchies are used in capacity planning to cumulate available capacity and capacity requirements.
You can cumulate available capacities from subordinate work centers to a superior work center level in order to determine the total available capacity for the superior work center.
Example
In your factory you have several lathes. You create a higher-level work center, called "Machine center 3", which you use to cumulate the available capacity of several lathes.
Portraying Hierarchies
You can display a hierarchy in work center maintenance or hierarchy maintenance as a list or a graphic.
As a list
The work centers that belong to a hierarchy are listed together with their hierarchy level. Refer to Displaying Hierarchy Structure as a List
As a graphic
The hierarchy graphic displays the hierarchy as a tree. Refer to Calling up a Hierarchy Graphic
In work center maintenance you can only display the hierarchy structure, in hierarchy maintenance you can also edit the structure, for example you can delete or change work center assignment.