I support a government customer who is about to embark on a major ERP implementation. I am currently providing cost estimating and analysis support to this customer in terms of what it costs to implement an ERP solution. In my research I have found several metrics to use in estimating as well as several identified risks concerning implementation. However, I was wondering if anyone who has actually been involved in implementing ERP solutions has any advice concerning risks, estimating methods, etc. Thanks in advance.