We normally ftp the code to the target FMW server ( or move them through the Version Control System) - and deploy them using the deployment plans - which takes care of the deploying the metadata and the composites.
For the first instance we followed the full process - and then on we have just been using the deployment plans.
Further to add to Anish Statement follow the steps to easily migrate the code to different environment.
First log on to the EM Console and export the Composite Flow as a SAR file to a location.
In Jdeveloper create a project using the same name of a SAR file like - ProcessSalesorderFlow
import the project using the option import the composite using a SAR File.
After import , then click on the composite and then generate the config plan.
In config plan add all the url changes using the search and replace Tags.
And in case if you have a JCA Adapters the same has to be taken care in SIT environment why because during deployment a lookup happens and deployment fails if it dont find the JNDI Name.
Take the SAR file adn config plan seperately from JDeveloper.
Now open em console again and then deploy it using the config file and SAR file.