Process systems aim to support many people involved in many processes over a long period of time. They provide facilities for storing and manipulating processes in both the representation and enactment domains. This paper argues that process systems should support ongoing transformations between these domains, at any level of granularity. The notion of creating a enactment model instance from a representation is merely one restricted transformation. Especially when process evolution is considered the case for thinking in terms of model instances is weak. This argument is supported by our experience of the ProcessWeb process system facilities for developing and evolving process models. The idea of hyper-code, which supports very general tran...