How to enter Multiple Dates entry for single Row Qty in SharePoint List

Hi All,

I'm using SharePoint Online small and don't have access for Infopath or visual studio. I can only use SharePoint or SharePoint Designer . Here I've created a SharePoint List to maintain Purchase Order Data. 

In below screen shot if Order Total Qty Deliver in one time than user can easly enter the data in SharePoint list and it will show the Balance Qty as zero and easly I can track it by filter using purchase no. But here I'm confuse how to enter the Delivery Date& Deliver Qty in list (like one row) if Qty is deliver in different date (more than one time) like Purchase No 103, Part No 2026 because once enter the Deliver Qty it should show the Balance Qty also.

I'm not sure how to maintain the list for One Purchase No with different dates because after enter the Deliver Date & Deliver Qty If I will filter the data with Purchase No 103 it should show the record like how many lots or which dates we received the Qty, with Balance Qty. I tried to create another List with Lookup column but its not working (I think I'm not doing in correct way). 

Thanks