You can create new versions of your business process, so that multiple versions of those same processes can co-exist in a runtime environment.
To create a version of a business process, it is important that you plan ahead. Specifically, you will need to consider how the client interacts with the process, and how the process itself is set up. To allow for seamless introduction of new versions, it is a good idea to anticipate the need ahead of time, and set things up in the manner described in the associated topics.
Of critical importance, the two versions must have the same name and namespace, but have different valid-from dates. In addition, where applicable, they must also have the same interface, and correlation set specifications. In other words, it is with different valid-from dates that multiple versions of the same business process are distinguished. In practice, at runtime the process engine could use a new version of a process that is set to become valid today, even if an older version of that process was still being used.
When a client invokes a process, that client can be configured either to choose a specific version each time, or to pick up the currently valid version of the process. This is the basic concept behind early binding and late binding.
With early binding, a client is hard-wired to a process in such a way as to force a continued relationship between the two of them, even if another version of the process becomes available. In contrast, with late-binding the relationship between the client and the process is dynamic in that it is resolved in the runtime environment.
In other words, if the caller instantiates a process using early binding, a specific version of the process is used to create that instance, and if they use late binding, the currently valid version of the business process is used.
See the whitepaper on developerWorks called Versioning and dynamicity with WebSphere Process Server and the podcast called WebSphere Technical Podcast series: SOA programming model, Part 5: Managing change in Web services components and applications