Most companies have multiple OBS as a person can report to a manager for certain functions while this person at the same times report to other manager for other functions.
The electrical crew supervisor can report to the project manager for certain functions while at the same time he reports to the electrical division manager.
If you cannot account for multiple OBS the functionality falls short.
OBS functionality among other things is useful for orgamizing your scheduled e-mail notices and reporting that will deppend on your multiple WBS and multiple OBS as per your company standards or specific job requirements.
For example, if according to OBS:
According to OBS, opened in the Resource Gantt the user can create the following reports on the whole project, individual departments or resources:
Cumulative costs of departments, resources and assignments;
Working duration for departments and comprising resources;
Work volumes and resource-hours;
Individual resources work costs; cumulative costs or resources, comprising departments – in the context of cost components and cost centers;
Material consumption by resources and departments;
Consumption of materials, organized in material centers;
Resource hours of resources assigned to activities execution in resource-hours
Cumulative costs of departments, resources and assignments;Working duration for departments and comprising resources;
Work volumes and resource-hours;
Individual resources work costs; cumulative costs or resources, comprising departments – in the context of cost components and cost centers;
Material consumption by resources and departments;
Consumption of materials, organized in material centers;
Resource hours of resources assigned to activities execution in resource-hours