Adding flexibility to the rigid structure of activity-based workflow specifications while maintaining their positive aspects certainly is one of the holy grails of current research, and this paper offers one of the few truly integrated and novel concepts to address the problem.

The new blended approach is based on the crucial observation that process data (and conditions on this data) may be used to link and synchronize two well-known and broadly established modeling types: activity-based and goal-based workflow specifications.

In the activity-based view, the paper introduces the input and output data of activities as pre- and post-conditions, independent of the control flow. The complementary goal-based view arranges business goals in a tree-like hierarchy of goals and sub-goals, eventually terminating in certain conditions on (and this is crucial for this method to work) the very same data objects used in the activity-based view.

Standard behavior is provided by simply executing the (pre-structured) control logic of the activity-based workflow model. In case exceptions to this control flow are necessary, the blended approach allows the workflow user to skip certain activities or goals ad hoc and add new goals. The user then “only” needs to ensure that at some later point in the process all required data for a downstream activity, or a (sub-) goal, is available (for example, by manually filling out an electronic form).

The author convincingly presents this approach in an informal style (that is, non-mathematical or non-model-theoretic), which is still suitable for all informed stakeholders in the workflow modeling or automation communities. As a matter of fact, the only thing currently missing is an actual implementation of this concept in a workflow engine. Given this lucid outline, I am confident that will happen soon.