Planning Horizon 
To determine the periods for which the system calls the scheduler workplace, you can enter one planning horizon for demands and one for resources.
Example
The time period displayed for the item and order worklist for demands can contain four weeks, while the time period of the bar chart for the current resources only displays the next seven days.
In Customizing for SAP Multiresource Scheduling, you have defined the planning horizon at .
You specify the default period in Customizing at . The planning horizons for resources and demands move depending on the date and the values defined for them. The default period can be overwritten in the following locations:
To change the default periods before you start the planning board, you activate a dialog box that is displayed before the scheduler workplace opens. To do so, choose in the scheduler workplace and set the indicator Access via Period Dialog Box.
If you enter other periods in the input fields of the planning board under , the system uses these as the default periods.
To change the periods for your current session, you can choose
(Change Period) in the planning board or use the menu option to change the periods for the current view. These settings are lost as soon as you close the scheduler workplace.
You can also select periods on the initial screens of the planning board via resource planning nodes (/MRSS/PLBOORGSRV) and planning board – general (/MRSS/PLBOORGM) transactions. The system displays the planning horizon values from the user settings as the default values. If no values have been defined there, it displays the values from the IMG activity Define Planning Horizon.
The planning horizon for demands is used to select demands only. For all other functions in the planning board, such as checks against the planning horizon, the system uses the planning horizon for resources.
If you want the demand horizon to be the same as the resource horizon, you can set the indicator Activate Planning Horizon for Resources Only.