An Organizational Breakdown Structure (OBS) is a pyramid- or tree-like structure which describes the relationships and work responsibilities of the people in your organization. The highest level of the OBS is the top level of management. The organizational structure is progressively detailed downward to the lowest level.
Within the OBS, two separate organizational hierarchies (or trees) are available to provide detail and summary project data through the company organizational structure:
A performing organization tree reflects the hierarchy of reporting within a company or "line" organization.
A responsible organization tree is for projects that employ some degree of matrix management. The Responsible OBS can be a functional category such as engineering, production, management, or manufacturing.
Some projects use both trees while others use neither, managing the project within the WBS framework only. You may create one or both types of OBS tree for each project.
If you are using both performing and responsible OBS trees, MPM treats them as separate organizational structures.
When you create an OBS element, you specify a parent department ID. Child departments become parent departments and their parents become grandparents when you assign them subordinate departments.
In the example below, Engineering is a parent of Department 600 and a grandparent of Departments 601 and 602.
When creating the WBS, you assign the WBS tasks to the OBS departments to create the Responsibility Assignment Matrix (RAM), typically matching work package WBS tasks with the Performing OBS departments, and control account WBS tasks with the Responsible OBS departments. For details, see Introduction to WBS.
When estimating, burden templates are used to add indirect costs. You can assign a burden template to a department in the OBS, which is then used in Integrated Planning when creating the Baseline and ETC estimates.
If you assign the burden template to the resource (in the Resources and Burdens window under the Globals tab), that burden template is used during Integrated Planning. However, if you don't assign the burden template to the resource directly, the burden template assigned to the resource department in the OBS is used.
For more information about entering burden templates and resources, see Defining Burden Templates and Defining Resources.