A transactional activity model for organizing open-ended cooperative activities

The authors propose a transactional activity model (TAM) for specification and management of open-ended cooperative activities. In contrast to each of the extended transaction models which focus more on a formal template for data processing patterns in an application, the activity model contains a set of formal templates, namely activity patterns, for capturing patterns of object interactions in an application. Using TAM, users may form new activity patterns by combining components of different existing patterns using activity pattern refinement and activity pattern composition mechanisms that include splitting and joining of activities. In TAM, activity histories are used to study the correctness of activity execution and activity restructuring through refinement, composition, split, or join.