Chesklist For Estimating Magneto Upgrade

• Number of enabled extenstions.

  For each extension check.

  • compatibility with Magento version you are upgrading to [CRIT]
  • class rewrites
  • layout updates
  • addition of foreign keys in install scripts

   

• Custom theme

  • if upgrade made from version before 1.4 [CRIT]
  • if layout XMLs are overwritten

   

• app/code/local/Mage [CRIT]

• core modifications [CRIT]