FM Activation for a Co code already gone live

Dear Experts,

We are planning to implement Funds Management for a Another utility client.

Here they have already implemented MM and FI (with interface with Maximo) last year.

Within the client they have around 5 company codes. we don't want it impact other co codes

Now since Fund Management activation is at client level ,will it affect other company codes ?

Also Commitment item and Fund center will be become mandatory for all postings.

We want to implement it only for one co code. There is a config where we assign FM area to co code.

Also what will be the impact of the earlier data in MM and FI ? There will be data for around 1 year..

Will the data before FM implementation be impacted ?

Please Advice.

Regards

Gautham.