Field help (HRZEXE) 

This field is used to define a calculation horizon by specifying the number of fiscal years for which the calculation processing will have to be performed. For instance, 5 means that the software will determine, during the calculation, the charge for the current FY and for the next four FYs.
This value is loaded by default with that of the following parameter: NBEXESTO - Number of FYs to be stored. It has to be greater than 2.

It is used:

SEEWARNING This value has a great impact on the calculation processing times. For more information on the calculation optimization terms, refer to attached document:Calculation optimization.