To use project-specific cost objects

Project-specific cost objects only refer to a particular project. Project-specific cost objects are typically derived from a similar standard cost object so that you can copy details from standard cost objects and make changes where appropriate.

If the project cost object is derived from a standard cost object, you can delete the project cost object, automatically the standard cost object is used. This can be performed even if the cost object is in use. A project item cannot fall back on the standard item, because the project item has a different code from the standard item.