Sum values that match in different rows

[rlobera]

Hi guys!

I need some help regarding an issue that I was not able to solve. I tried to figure it out but without reaching my goal. This is what I have:

In sheet 1 I have estimated active customers for a period of time, where columns are months and rows are departments/states:

[TABLE="class: cms_table_grid, width: 500"]
<tbody>[TR]
[TD][/TD]
[TD="align: center"]Month 1[/TD]
[TD="align: center"]Month 2[/TD]
[TD="align: center"]Month 3[/TD]
[TD="align: center"]Month 4[/TD]
[TD="align: center"]Month 5[/TD]
[/TR]
[TR]
[TD="align: center"]Department A[/TD]
[TD="align: center"]3[/TD]
[TD="align: center"]6[/TD]
[TD="align: center"]10[/TD]
[TD="align: center"]14[/TD]
[TD="align: center"]15[/TD]
[/TR]
[TR]
[TD="align: center"]Department B[/TD]
[TD="align: center"]2[/TD]
[TD="align: center"]5[/TD]
[TD="align: center"]8[/TD]
[TD="align: center"]13[/TD]
[TD="align: center"]20[/TD]
[/TR]
[TR]
[TD="align: center"]Department C[/TD]
[TD="align: center"]4[/TD]
[TD="align: center"]6[/TD]
[TD="align: center"]7[/TD]
[TD="align: center"]9[/TD]
[TD="align: center"]12[/TD]
[/TR]
</tbody>[/TABLE]


Then, in sheet 2, I'm forecasting sales and need excel to return values from sheet 1 depending on which month we are kicking-off for each department:

[TABLE="class: cms_table_grid, width: 500"]
<tbody>[TR]
[TD="align: center"][/TD]
[TD="align: center"]Kick-off[/TD]
[TD="align: center"]Jan[/TD]
[TD="align: center"]Feb[/TD]
[TD="align: center"]Mar[/TD]
[TD="align: center"]Apr[/TD]
[TD="align: center"]May[/TD]
[TD="align: center"]Jun[/TD]
[TD="align: center"]Jul[/TD]
[/TR]
[TR]
[TD="align: center"]Department A[/TD]
[TD="align: center"]Jan[/TD]
[TD="align: center"]3[/TD]
[TD="align: center"]6[/TD]
[TD="align: center"]10[/TD]
[TD="align: center"]14[/TD]
[TD="align: center"]15[/TD]
[TD="align: center"][/TD]
[TD="align: center"][/TD]
[/TR]
[TR]
[TD="align: center"]Department B[/TD]
[TD="align: center"]Mar[/TD]
[TD="align: center"][/TD]
[TD="align: center"][/TD]
[TD="align: center"]2[/TD]
[TD="align: center"]5[/TD]
[TD="align: center"]8[/TD]
[TD="align: center"]13[/TD]
[TD="align: center"]20[/TD]
[/TR]
[TR]
[TD="align: center"]Department C[/TD]
[TD="align: center"]Feb[/TD]
[TD="align: center"][/TD]
[TD="align: center"]4[/TD]
[TD="align: center"]6[/TD]
[TD="align: center"]7[/TD]
[TD="align: center"]9[/TD]
[TD="align: center"]12[/TD]
[TD][/TD]
[/TR]
</tbody>[/TABLE]


Of course, the kick-off month may vary for each department and values from sheet 1 should accommodate according to the selected month on column B in sheet 2.

And within C2:I4 I have used this formula:

=IFERROR(IF(C$1>=$B2,INDEX(Sheet1!$B$2:$F$4,MATCH($A2,Sheet1!$A$2:$A$4,0),MONTH(C$1)-MONTH($B2)+1),""),"")
The formula above actually works great when departments are not repeated in sheet 1 but, what would happen if departments are repeated and I have to sum values from the same department and show the result on each cell in sheet 2?

I look forward to your kind help!

Thanks!