The system carries out an ex-post forecast for the initial forecast if more past values are available than are required/are to be used for initialization. It also carries out the ex-post forecast during parameter optimization, model initialization and for evaluating the accuracy of the forecast.
The system only carries out the ex-post forecast for subsequent forecasts when there is a gap of more than one forecast period between the last forecast date and the current forecast date. For technical reasons, the series of forecast values must be recalculated for every period. Since this requires a lot of time and effort for articles which are forecast daily or weekly, you can now make up for periods which you have "omitted" from the forecast. This means that it is no longer necessary to carry out the forecast for each period as the missing values can be provided by a later forecast. This is then achieved with the help of the ex-post forecast.