Column Based On Other Column (short Name Based On Name), When To Do The Transformation?

Hi!

I am designing a dimension table which will include a short name column based on the (full) name column. For example say Product dimension where I will have ProductName and ProductShortName. ProductShortName will be the first 6 characters of ProductName. I could populate ProductShortName using:


Substring in the select when I select from the original system, e.g. SUBSTR(PRODUCT_NAME, 1, 6) AS ProductShortName

Create a derived column in the SSIS flow which does the same thing

Create the ProductShortName column as a computed column which uses substring on ProductName

Create a trigger that populates ProductShortName based on ProductName when a row is inserted or updated

Create a named calculation in the table in the Analysis Services project's data source view

Create a named query in the Analysis Services project's data source view

I usually use 1, and 5 or 6 would only be used if I only will create reports against the cubes. 3 seems easiest to maintain, so I am thinking about using that one, but maybe it is slow for the data flow as I imagine it must be something like using 4, or when is the column "created" at runtime, i.e. when the table is queried?
Which approach(es) do or would you use? Pros and cons?

Thanks!