Work Breakdown Structure (WBS)Definitions: Work Breakdown Structure is a tool project managers use to break projects down into manageable pieces. Here's why you need one and how to create your own. Awork breakdown structure (WBS), inproject managementandsystems engineering, is a deliverable-oriented decomposition of a project into smaller components.Organizational Breakdown StructureDefinitions: An organizational breakdown structure is a document that your business can use in conjunction with its workflow schedule and resource breakdown to organize the people who will be working on a particular project. The OBS details who reports to whom, the details of the hierarchy and the reporting structure.OBS Design: Organizational breakdown structures are normally communicated visually through the use of graphs or charts. A project or general manager is listed and underneath the PM several divisions might be created, such as product development, design, materials management and production. Under these divisions might be several sub-categories or names of employees listed directly under the larger divisions. You can think of the OBS as a tree; each branch indicates a working relationship and lateral communication responsibility. The nearer to the top of the OBS that a person is, the more likely that person is to have broader responsibilities.