enabling the segment in the oracle application

In 11i our client is adding the segment Product group in the structure in the middle of the year.

because of this the enabling the PG for the below account.

Charge Account

Inv. valuation - Material

Inv. valuation - Overhead

Purchase price variance or rate variance

Invoice Price Variance 

let me know what are all the steps to be taken care be for implementing and approches can be taken at subledgers and impact analsys on the business.

Thanks in advance.