I am having some issues trying to implement an average of a dimension attribute.
The basic structure is:
On the booking header dimension I have a numerical attribute called Booking Window, and I want to be able to create a calculated measure that averages this value.
We are using SQL Server 2012 standard edition.
Any help would be greatly appreciated.
The best approach would be to create a measure group from the dimension table (in BIDS, go to cube designer, tab "Cube Structure", right-click the cube object in the Measures list, and select "New Measure Group", select your dimension table). BIDS will generate some measures, and you can remove all but two: the one based on your numeric attribute (I will call it "YourSummedAttrib" to have a name to refer to below), and the count measure. The aggregate function for the measure "YourSummedAttrib" will probably be "sum", leave that as it is.
Then, create a calculated measure which divides "YourSummedAttrib" by the count measure, which gives the average. Finally, if you have tested everything, make the two measures "YourSummedAttrib" and the count measure invisible before you give the cube to the users, as they only need to see the average, which is the calculated measure.