In SAP S/4HANA, awork center hierarchy(transaction CR21/CR22) organizes work centers for capacity planning and evaluation:

A group of alternative work centers providing a cumulative available capacity for production(B): A work center hierarchy groups multiple work centers (e.g., CR01-defined centers) into a tree structure (e.g., a top node with sub-nodes). The system aggregates their capacities (visible in CM01) into a cumulative total, allowing planners to evaluate or assign production across the group as a single capacity pool, often used in bottleneck analysis or reporting.

Hierarchy levels by priorities(A) isn’t correct—priorities are set in routings or PP/DS, not hierarchies, which focus on capacity aggregation.Work centers in a production line sequence(C) reflects routing (CA01) or REM line hierarchy (LDM1), not a work center hierarchy.Parallel sequence for splitting quantities(D) is a routing concept (Parallel Sequence), not a hierarchy function. This is per SAP’s capacity planning documentation.