data have; infile cards ; input PartNumber$ LineNumber ; cards; A 01 A 02 A 03 A 01 A 02 A 01 A 02 A 03 A 04 A 05 B 01 B 01 B 02 B 01 ; run; data want; set have; by partnumber ; retain group; if first.partnumber then group=linenumber; else if linenumber=1 then group+1; run; ... View more

Thank you for your explain! Yes the second timing problem is shown in this case. I'll also be care about the first timing problem. I really think maybe SAS can consider to make some change so that the program runs in the order it looks like. ... View more