How to chage the source code of the website without impacting google rank

[ggiaisme]

Hi everybody, I want to change my company's website to drupal from zend. But I scare it impact to google rank, pagerank, ...

I am thinking of this solution:
 - I will save all the page of current website (from browser -> save as), upload it to hosting. So I can keep all the pages with the same current Urls. They would be static pages
 - I will work on the homepage (drupal platform) and create new pages to replace the static pages step by step.

But I don't know what will happen with the google rank, pagerank, ...

Can anybody advice me if its good solution? What would be good solutions for this case?

Thank you all
(The website is www.intour.com.vn)

[convergent]

- I will save all the page of current website (from browser -> save as), upload it to hosting. So I can keep all the pages with the same current Urls. They would be static pages

Wonder if your website will be workable. Anyway if your links will be absolutely the same there will be no impact to Google

- I will work on the homepage (drupal platform) and create new pages to replace the static pages step by step.

Look Google webmaster help https://support.google.com/webmasters/bin/answer.py?hl=en&answer=83105

In general i suggest you to make first test version on test hosting account and duplicate your website there. If URL structure changes use 301 redirect not to get 404 errors when navigating from SERP. Don't forget to close test version from Search Engines in robots.txt.

[gomez]

All 'pages' are 'static' no matter how they are created, but if you mean static looking URIs  with Drupal ...

[damponting44]

The principal thing you should do is consider SEO. Time after time customers don't stop to consider the SEO effect of changing their site. They throw away significant substance from chronicled pages or choose it would be a smart thought to totally change each and every URL without diverting the old ones.