If you want to reverse GI from EWM and close ERP document, first you will go to transaction /scwm/tu and select action-check point-reverse departure and save. This is the reversing outbound from ERP system. then choose loading bottom and select reverse loading end.
If you want to change Hu or close document completely, you will cancel picking.
now you will change HU with cancel task then create new warehouse task or you will cancel all HU (warehouse task and change quantities with "0" and save. herewith you will close EWM and ERP documents.
Best regards.
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