Need Advice to Improve Performance of Import Processes

Hi,

We have received a client requirement to Process 20 million Supply chain Items to Oracle Fusion. As a part of PoC we have received 7,31,000 Items to load. We have split the records into 4 batches of 100K, 200K, 300K and 131K records. And for us to process 300k Records it took 2 Hour and 41 mins for Item Import process to complete. And as an average it is taking 1 hour to process 100K records. We need your advice to improve the performance and to decrease time taken for import by changing any setup, Params or any performance tuning