It depends. If you intent to use the survey data in more dashboards then it makes sense to create a separate qvw document that reads in the data from the csv file and transforms the data and then stores it in one or more tables. If you have to create different data models because different calculations and transformations are necessary that won't logically or practically fit in one script then create separate qlikview documents for extracting (1 document) and transformations (2 or more documents). My guess is that you can work with one document and do all the loading and transformations in one document. Use separate tabs to break up the script in logical chunks.