When is a work breakdown structure MOST useful?

A Work Breakdown Structure (WBS) is most useful when managing projects with multiple work packages that involve a combination of internal and external resources. The WBS helps in organizing and defining the total scope of the project by breaking down the project deliverables into smaller, more manageable components, facilitating better planning, allocation, and control of resources.References: (PRINCE2® 7 Foundation Handbook, AXELOS)