PR_Report IBP to S4 and PR modification

Hi Everyone,

We are utilizing infinite heuristics to make the readying numbers successful SAP IBP which further gets passed to S/4 successful signifier of a PR, we person 2 concerns successful the process :- 

1) How tin we modify the acquisition requisition which person already been passed from SAP IBP and punched successful S/4 ? For illustration - PR 410000982 generated successful S/4 for Product A astatine Location B from vendor C, transportation day connected 7th Aug, 24 for quantity 150 Units, however tin we alteration the quantity from 150 to 180 by AMMENDING the numbers successful SAP IBP.

2) Any modular study for the generated PR ? for illustration - 100 records were passed from SAP IBP to S/4 of which 98 got created, 2 got dropped for XYZ reasons, SLG1 is not bringing immoderate results.