A process modeling tool for graphically representing a process which includes transactions and events, and for generating computer code representing the process. A graphical tool creates a graphical representation of the transactions and events with graphical symbols, where one or more of such transactions and events may be of an asynchronous nature. A code generator generates computer code in response to information contained in the graphical representation. The computer code is executable on a computer system to cause the computer system to perform one or more operations which emulate the process shown in the graphical representation.