If you are using environment variables in SSIS when using package configuration, chances are you will run into a situation where you add or change the value of an environment variable, and SSIS does not recognize it. There is a misconception that in order for the packages to start recognizing it, the machine needs to be restarted. The reality is that just the process which is running the SSIS packages needs a restart. Typically this is the SQL agent if you have a job that is executing the package, or you will need to restart the SSIS service if you are running the package directly. In a development environment, BIDS would need a restart.
General Technology Tips · · · ·
I suppose this will need a bit more explanation. The way this tip is currently given, not very clear.