Discussion on:

Four rules to maintain ERP sanity

Here's an addition to number 4: but customization is not. If you have to customize to integrate there are other issues you need to address.

Here is a number 5 that I have seen prove true so many times: 5 - All your current processes must be documented and up to date.
If not, how do you expect to use them in a newly designed and built ERP system.

Great article!