Hi,
You created new company code YYY, so better create new plant P002 and then assign to your new company code YYY.
Any open transactions from company code XXX with plant 0001 can transfer to new company code YYY with new plant P002.
NOTE: If you are just changing description of company code XXX and plant 0001, then keep changing or if address changes are required - you can do it in old setting of codes XXX and 0001.
Regards,
Biju K