SSIS allows parallel execution in two different ways.
2 proporties controll the parallel execution of SSIS tasks.
MaxConcurrentExecutables, – This is a property of the package. It defines how many tasks (executables) can be executed simultaneously. It defaults to -1 which is translated to the number of processors plus 2. While doing this, you server hashyperthreading turned on, it is the logical processor rather than the physically present processor that is counted .