Abstract: A machine readable form of a design document is described which may be used in automatically generating a user interface for a service. In an embodiment, the machine readable form of a design document is generated by adding attributes to functions which make up the service. These attributes define the dependencies between functions, including the flow of data between functions and any required user input for execution of the functions. An extended service description, which includes details of the application logic of the service, may be generated automatically from this machine readable form of a design document and the extended service description may be used to automatically generate a user interface for the service.