SharePoint Farm Migration Looop

Recently i have finished my SharePoint Farm Migration from 32 bit OS to 64 bit task.
There were lot of things to share.
Let me share you loop which i use as action plan for migration on Live Production Farm.
We had 20 Major Portals...mean 20 web applications.

So, what i did

For Portal=1 to 20
{
1- Plan a portal lock time (Read only ~ 3 hours)
2- Notify Power User & Account Admin
3- Send an interruption message to the affected site
4- On the planned time:
a. freeze the portal (Read Only)
b. Backup the portal from the current production farm
c. Restore it to the test farm
d. Check the design
e. Do a random test
f. Send a test link to the power user
g. If it is ok, do another restore to the new production farm
h. Do a test on the new production
i. If it is ok, update DNS record to the new IP
j. Check with power user for confirmation
k. Send a service back notification
l. Stop the old portal on Old Servers
loop
}