Collective PO : Automatic distribution during Goods Receipt

Dear Experts ,

We have an IS Retail platform wherein we use collective purchase order process . The details are as under :

1. Create STO1  with site A as receiving & site B as supplying site  & STO2 with C as receiving & site B as supplying site
2. Create PO  through tcode  WF10 with site B as receiving site & Vendor V1 . This PO would collect the requirements of STO1 & STO2 . Relationship between PO & STOs will be mapped in table FRET .
3. Create GR document against PO  through tcode MIGO / MB01
4. Create adjustment against GR of PO through tcode WF50 . This transaction distributes the GR qty to STO1 & STO2 & created outbound deliveries against STOs .

My requirement is :

Create outbound deliveries automatically when the GR against PO is done . That is step 4 would automatically happen as soon as step 3 is executed .

There is a standard functionality available in SAP to meet this requirement. Can anyone please suggest what could be the steps & prerequisites for the same .