I would start with the inventory transactions. Different modules like WIP, OM and other external applications populate the MTI tables. The inventory interface manager (transaction manager - INCTCM) runs and validates the data and inserts the records into MTL_MATERIAL_TRANSACTIONS_TEMP table. When the transaction worker processes the temp data, the records are inserted into the transactions history table (MMT).
When the Cost Manager runs, it costs the transactions, and creates SLA events. Pl note in 11i, the cost manager used to create accounting as well.
When the Create Accounting (Cost Management) process runs, it creates the accounting. When the transfer to GL is run from SLA, it transfers all the accounting data to GL.