I did a series of reports (for one customer) focused on the sales side (component requirements), with multi-layer bills, and can say it was 100% impossible without SQL Views to deal with the data complexity.  If you only have single-layer bills, I suppose a sub-report could pull in the open PO details for whatever shape of main report you are starting with.

Thanks for your quick reply. I'm going to look into this tomorrow.  Should I assume that you're a SAGE consultant? or user?

Hover your mouse over my picture, and you can see that I am a Sage partner / consultant.

I have a customer where we did a version of this with PO. Their specific requirements/request was to add a UDF on the PO Header - UDF_Delayed. This is a checkbox and when they check the box the PO shows on the report and beneath it are the impacted Sales Order ( with open quantities awaiting fulfillment ).

There is no one place, for example, to find the next PO you expect to arrive for a given inventory item and how many are expected. This all had to be done via reports and form modifications ( yes there are third-parties that offer much better reporting ).