The business flow (BF) feature allows you to generate accounts by looking back at accounts previously generated for transactions/accounting that came before the accounting event you are currently processing. Journal line types (JLT) that are business flows do NOT have account derivation rules (ADR), ie the account is not created at this event point but looked up from a previous event.
When would you use BF instead of ADR?Its all about timing, BF takes an account previously generated, ADRs builds the account with sources that are present NOW. Sources can change during the life-cycle of the transaction and the ADR may generate different accounts at different points in time.
Example in seeded SLA rules is the reversal of PO encumbrance when an AP invoice is validated. The PO reversal JLT is BF which gets the account from the journal that reserved the PO.
PS Another nice side effect of using BF is that there is a “link” in the SLA tables back the transactions that it use to get the account. (applied_to_xx in distribution_links)