What is the best way to upgrade a Drupal 5 web application to 7?

I am trying to work out what is the best way to upgrade www.edocr.com, which is built on Drupal 5 to Drupal 7. We are more than a mere website.

If the answer is, start new with Drupal 7 and then import content, this also opens up another question, i.e. should we ditch Drupal completely and use a php framework such as http://www.yiiframework.com/, which would of course be a costly exercise. Could we achieve the same level of performance that a framework such as yii could offer through Drupal 7?

Many thanks in advance.

I've had to do upgrades from 5 to 7 and this is my experience. Upgrade everything, piecemeal to 6, then to 7. The schema changes between 5 and 7 are huge and you don't want to miss anything. That is going to be a cost to you.

If you have a content specialist, create a separate Drupal 7 site and then have the specialist recreate the content in 7 from scratch. This has the added benefit of everything being clean in 7 and you don't have to worry about schema changes during upgrades...this is a cost to your client.

As far as frameworks versus Drupal, it is a wash either way. Drupal is free, but the time for supporting it is not. You spend more time figuring out how to do things in Drupal than developing. Whereas with custom frameworks, you get the benefit of doing it yourself the way you want, but at a longterm cost of having to support the code over the course of its lifetime.

I'd say, if your client is happy with the modules, they can accomplish what they want in Drupal, and there is nothing prohibiting you from getting your messsage across, stick with Drupal. But if the system is coming up short in lots of areas, definitely weigh the cost of developing and supporting custom code to time spent customizing Drupal....remember, free software is only free at the outset...not longterm.

The general way of updating a Drupal site for a major Drupal release is to:

1. Upgrade Drupal core
2. Upgrade contributed modules.
3. Upgrade theme / create new theme

In your case you need to do 1-2 twice and 3 once. It also becomes a bit tricky since, you might be missing modules from D5 -> D6 and D6 -> D7. You will need to do some investigating as some modules are merged in new Drupal releases, while others just disappear.

You can try out doing the 1-2, 1-2 a few times a see what happens. It might give you an indication of how much work is needed to actually get your site upgraded.