Frequent changes in customer master

Hi All,

I've analysed absurd discrepancies of shipment key figure (601 movt. type) b/w ECC and APO planning book, i took the most affected material numbers and found they all being sold out to same customer number and that customer master has been changed quite frequently.

Could frequent changes in customer master data be the reason for the discrepancies b/w the two systems KF data? if yes what measures can we take to prevent this?

Regards

Kartik