Sorry if this has been covered but I have a spreadsheet with shift A B
or C in col A. A part number in col B and the quantity of each part in
col C. Each shift can do a number of part numbers in a shift and what
I need is a formula in D which will add the number of parts produced
for each shift e.g. subtotal col C for every change in Col A.

A B C D
Shift Part No Qty shift total
a 123 23
a 23 45
a 21 13 81
b 323 45
b 23 23 68

Hope this makes sense

Thanks in anticipation of a solution
Martin