In a nutshell, a 'what if' analysis looks at historical, predicted or budget data and then adjusts this actual data by one or more factors to show a 'what if' value.
At it's most simple it may be adding a percentage shift (say +10%) to last years figures to predict the next years. This in itself does not reveal much. You could look at a composite shift, so say you expect sales to go up by 10% but costs to rise by 15% with margins being shrunk by prices only rising by 5% - when all that is layered on top of your existing data what does the picture look like?
I have done analysis where the user requested that they could apply a different offset to each of the territories in their data - again the composite picture of those different adjustments could be seen.
Often these offsets are set using variables and QlikView slider objects. These however take up a lot of space on the screen - so sometimes a simple input box with numeric constraints on is a better approach.
