How to do data cleansing in DvSum? Once you have identified exceptions, you can use DvSum cleansing capabilities to fix the data and write the data back into the source. Data Cleansing rules could be fixing individual exceptions or applying mass update rules. Once changes are made, DvSum will write the changes back to source system, whether it is files, databases or to applications like SAP ECC, Oracle Ebiz. Approval process can be optionally configured to orchestrate an update process where fixes can be approved or rejected, before applying the changes to source systems.