Last night I spent an unnecessary 90 minutes at work 'after hours'. Without boring you with all the details, I selected 'Yes' at an option that seemed sensible when I was creating a new model for 2012. However, loads of items copied that should not have done. So the 90 minutes was spent breaking links, replacing other items & rebuilding links.

'Just for fun', I created another copy today & selected 'No' instead. The model created in about a minute & within 10 minutes I'd updated all of the week one data.

Lesson learned for next year.