In recent times western economies have become increasingly focussed on knowl-edge work. Knowledge work processes depend heavily on the expert knowledge of workers and therefore tend to require more flexibility then the processes seen in traditional production work. Over-constrained processes cause frustration and inefficiency because they do not allow workers to use their expert experience to make the best judgements on how to solve the unique challenges they are faced with. However some structuring of their work is still required to en-sure that laws and business rules are being followed. IT Systems for process control have a large role to play in structuring and organizing such processes, however most of these systems have been developed with a focus on produc-tion work and fail to support the more flexible processes required by knowledge workers. The problem arises at the core of these systems: the notations in which the processes are defined. Traditional process notations are flow-based: control of the process flows from one activity to the next. This paradigm in
