在不同的服务器上使用SSIS环境变量

I have read several articles about Environment variables but I can't find how to apply their usage in my case. I am developing SSIS packages on my local machine. Once they are finished I plan to deploy them on staging an production server. My SSIS project consists of several packages which most of them connect to 2 databases (but each server has it's own copy of db) and few excel files.I have read several articles about Environment