Mike,

There are probably no aspects of business logic that could not be written as transformations and fully described in XML. But so what? I could build a reproduction of an 18th century desk using nothing but hand tools in weeks or using power tools in mere days. Unless I am looking for a special effect that only hand tooling can provide, I am going to use power where possible. Its just more efficient and the result is the same -- a reproduction desk that has essentially the same "deskness" independent of the processes used to build it.

XML or any scripting language, is not efficient at developing complex applications. An OOP language makes it easier, faster, and usually more error free, and is therefore more efficient and the better choice.

Using XML where it is most efficient, e.g. translating data between incompatible data structure or through media that most effectively handles scripting, is preferable to stretching all reason to translate every transation to XML.

So, my answer to your question is: Yes, it could be done, but why bother except to maintain a thesis at all costs.

By the way, why would you store calculated results when they may simply be recalcuated when required?

Regards,