Moving to PowerPivot question

[udigold1]

Hi there,
I'm considering to start working with PowerPivot but I'm concerned with the way historical data is handled.
Today I use several excel files (VBA programmed) which have data and many conversion tables. They are backed-up on daily basis on my network, so if I want to see what was a year ago, it's available on my network folder - and it's static, meaning If I changed the conversion tables on date X, It will apply from Date X onward, and won't change what was before.

If I'll move to PowerPivot and the DataModel, the conversion tables will be on the DataModel and if I need to change the conversion table it will affect all data and dates - and that's a big problem, since I have to keep a copy of the original as it was at the time (before applying a change to the conversion table)
How can I do that with PowerPivot?

Thank you,

 

[Matt Allington]

If I'll move to PowerPivot and the DataModel, the conversion tables will be on the DataModel

I guess it depends how you load the data you could leave your conversion tables where they are and just load the converted data. But it depends on the structure of your data