The Visual Basic for Applications library functions are a great way to extend the functionality of your MDX  statements, allowing you to do some very handy stuff. Irina Gorbach has created a nice little document outlining the VBA functions available, so definitely check that out. There’s an important performance difference between the VBA functions and native MDX functions, which Irina points out.

One of the VBA functions I’ve been asked about by a couple people is the IsNumeric function. The IsNumeric functions returns a Boolean value indicating whether an expression can be evaluated as a numeric value. Here is an example (using the AW example cube) of how one might utilize IsNumeric:

With Member [Measures].[LastOrderYear] as

IsNumeric([Reseller].[Reseller].CurrentMember.Properties("Last Order Year"))

Select [Measures].[LastOrderYear] on 0,

[Reseller].[Reseller].children on 1

From [Adventure Works]

And here is what the results look like:

So check out the Irina’s document on the SSAS VBA functions. I think you’ll find it very informative and useful.