Hi TPT,
It is the discretion of the business to determine the accounts for which OIM need to be activated. However, SAP has in principle provided an example in F1 help of the field in transaction FS00.
Clearing accounts:
Bank clearing account
Payroll clearing account
Cash discount clearing account
GR/IR clearing account
Also it mentioned about the type of accounts for which OIM should not be activated.
So, you can consider these principles for deciding the business process to identify your list of accounts to be on OIM. And the basic criteria should always be the business necessity of doing clearing in the account. So if none is actually feeling the necessity of clearing and none is actually doing clearing of an account, then you can proceed to deactivate OIM for the account.
I believe these principles in total will help you to frame the business policy with regard to OIM activation for your accounts.
Regards,
Sridhar