The following overview describes the basic hierarchy of the menu bars at the three levels of the R/3 System, the main menu level, the application level, and the task level. The task level itself can have a hierarchical structure, too. Structure the menu bar uniformly within a task to ensure consistency. Therefore, do not remove functions that are not used from the menu bar and the pull-down menus but set inactive only.
Note: The System and Help menus are always available in the R/3 System. They are appended automatically to the right of the individual menus at the respective level. The same applies to the Layout menu, which appears to the right of the menu bar as icon. It allows the user to change local settings like fonts or interface colors.
Main Menu Level
In the menu bar at the main menu level, the R/3 System displays all application areas available. The following application areas are currently available: Office, Logistics, Accounting, Human resources, Information systems, Tools.
At the application level, object classes or tasks = transactions of an application area are listed in the menu bar.
For guidelines on how to design a menu bar on the application level see Menus at the Application Level.
At the task level, the user edits data. The structure of the menu bar and the corresponding pull-down menus are largely standardized. In the following you find an overview of the individual menu bar options in the defined sequence from left to right, together with a short definition and obligatory or typical pull-down menus.
For a detailed description of the menu strcuture at the task level see Menus at the Task Level.
Source: SAP R/3 Style Guide