A Transactional Activity Model for Organizing Open-Ended Cooperative Activities

We propose a transactional activity model (TAM) for speciication 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 diierent existing patterns using activity pattern reenement and activity pattern composition mechanisms that include split and join of activities. In TAM, activity histories are used to study the cor-rectness of activity execution and activity restructuring through reenement, composition, split, or join.