I see several issues with the variable initialization in Assign. Some are ease-of-use related, others seem like bugs. I have written a JIRA for Riftsaw, https://jira.jboss.org/browse/RIFTSAW-301 that requests automatic initialization of variables inside the engine. This is one approach to addressing variable initialization problems (moves the responsibility to the engine). In that JIRA I have also noted examples where the BPEL Editor said a copy operation was in error that executed fine on the server, as well as not flagging errors in a copy operation that threw an Assignment Fault at runtime. In general the relationship between the initialization (which is done through a copy operation) and well as the actual assign copy operations, is too confusing for the average BPEL Editor user. The user (we are not talking a business analyst type here, but a process architect / developer) should not have to worry about the syntax of these various copy statement and knowing whether they are correct. They should just be able to say which parts of a message get copied to which parts of another message. Either the tooling or the engine should take care of the rest.