Copying data from one document to other

Hi Guys,

We have requirement to copy the updated data in one of the fields from Change Document to successor document.

For eg a doucmnent of type SMCR was created with value ABC for field Projects(Custom Field) and follow up document was created having same custom field with value ABC.

But if now we update the value of the to DEF in SMCR it should update the value in successor document also to DEF but it is not happening.

Please advice how can this be done?

Regards

Abhishek