Updating Scheduling Data in the Material Master (Mass Changes) 
Use
You use this procedure to schedule the master recipes for several materials at once and update the scheduling data of the material master records.
The system always schedules forwards in this function, using the lot size as the recipe base quantity.
You can choose one of the following types of data transfer:

You can also update the scheduling data in individual material master records (see
Prerequisites
The procurement type External procurement has not been assigned to the material master records you want to update.
Procedure
.The system schedules the master recipes. The scheduling results are displayed in a list. Depending on the settings you have made, the results are also transferred to the material master or a temporary file.
Materials for which a scheduling error occurred are marked correspondingly in the list. The system messages for the different errors are collected in the error log.
For more information on the error log, see Displaying the Scheduling Log.