One formulas play which delivers the automated summary that you seek
Source data is assumed entered in A2:B2 down
In D2:
=IF(COUNTA(A2:B2)<2,"",IF(SUMPRODUCT((A$2:A2=A2)*( B$2:B2=B2))1,"",ROW()))
Leave D1 blank

In E2:
=IF(ROWS($1:1)COUNT($D:$D),"",INDEX(A:A,SMALL($D: $D,ROWS($1:1))))
Copy E2 to F2. Select D2:F2, copy down to cover the max expected extent of
source data, say down to F100? Minimize col D. Cols E and F will return the
required summary, all neatly packed at the top & dynamic to the source data
as it changes/adds on.
--
Max
Singapore
http://savefile.com/projects/236895
Downloads:21,000 Files:365 Subscribers:65
xdemechanik
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"tomhelle" wrote:
I have a spreadsheet that will constantly updated by customers. I want to
create a formula to automatically summarize a list of various components. For
example:

Column A Column B
Material 1 Thickness 1
Material 1 Thickness 2
Material 2 Thickness 1
Material 1 Thickness 1

I want a formula on the spreadsheet to summarize this data so that it will
produce a list as follows:

Column A Column B
Material 1 Thickness 1
Material 1 Thickness 2
Material 2 Thickness 1