Challenge: Vlook-up/match with a sumif

Ok so I have a challenging and complex spreadsheet formula. I have this formula and others where the date and the username changes. =SUMIFS(S1T1!E:E,S1T1!A:A,B2,S1T1!A:A,C2,S1T1!B:B,"Pick Item to WO",S1T1!C:C,"TULBRAZC").

I want to add the ability for when I type in the username in column b for it to match the values for that username from s1t1 and insert it in to the equation. This way if a person were to move shifts, all of the equations would calculate with emphasis on making sure the productivity works


Copy of mike new spreadsheet-MASTER.xlsx