Review and check the payroll on a pay period to pay period basis. Reconcile the result of the payroll run with the results of the previous period and explain the variance between the two results for key data amount total gross pay and total number of employees on the basis of HR master data changes (Amount previous pay period + salaries new hires during the period + all salary adjustments during the period -/- salaries leavers during the period = amount current pay period).