If you have a 6.1.x environment and are thinking about upgrading to 6.2, then you must read:

Migration to WebSphere Process Server and WebSphere Enterprise Bus 6.2 – Mandatory reading

WebSphere Process Server and WebSphere Enterprise Service Bus version 6.2 provide major functional improvements over previous versions, and in order to take advantage of these new features while preserving your existing applications and profile configuration you must migrate to version 6.2 of the product. WebSphere Process Server 6.2 is not a refresh pack or an upgrade version. Version 6.2 must be installed alongside the older version of the product. To facilitate your migration process, WebSphere Process Server 6.2 provides improved version-to-version migration utilities to help you migrate your existing applications and profile configuration information.