Comprehensive and Detailed Explanation (Paraphrased from Workday Pro HCM Core – Organizations and Staffing Structure Guide, 2023R2):

In Workday, every worker must belong to exactly one Supervisory Organization. The Supervisory Organization defines the management hierarchy and reporting structure for workers and positions. It serves as the foundation for staffing, business process routing, security role assignment, and approval workflows.

When hiring or transferring a worker, assigning them to a supervisory organization ensures that the worker’s manager, HR partner, and other role-based participants are correctly identified. Without this relationship, the worker cannot be successfully staffed or managed within the tenant.

Options B (Matrix), C (Cost Center), and D (Company) may also be required for organizational reporting or accounting, but only Supervisory Organizations are mandatory for all workers because they define managerial oversight and operational hierarchy.

Reference (Paraphrased Source):

Workday Pro HCM Core – Organizations Configuration Guide (2023R2), Section: “Supervisory Organizations as the Basis of Staffing Structure.”