This document provides guidance for work breakdown structures for organizations undertaking project or programme management. It is applicable to any type of organization including public or private and any size of organization or sector, as well as any type of project and programme in terms of complexity, size or duration. This document provides relevant terms and definitions, concepts, characteristics, benefits, uses, integration and relationships related to work breakdown structures. It does not provide guidance on the use of processes, methods or tools in the practice of developing and using a work breakdown structure. Annexes A and B provide examples of work breakdown structures and relationships to other breakdown structures.