ARIADNE and HOPLa: Flexible Coordination of Collaborative Processes

The Ariadne system and its modeling language HOPLa aim to provide generic support for hybrid collaborative processes, i.e. complex information processing tasks involving coordinated contributions from multiple people and tools. Ariadne should be usable for a wide variety of such processes and actively support people working in them and defining and managing them. The basic concept in Ariadne is that of a process. It combines a shared workspace with mechanisms to control the growth and evolution of this workspace. The workspace holds tree-shaped data and is selfdescriptive, in the sense that it holds the actual data but also the constraints (i.e. type definitions) that govern its structure. Nodes in the workspace can be marked as tasks to be performed and coordination operators and constraints, e.g. on the deadline or performer of a task, can be attached. Ariadne manages active processes and provides the interaction with the outside world. When tasks are enabled, actors are notified and results of their actions are stored in the workspace. A key issue for Ariadne is flexibility. It should be easy for users to model and create new kinds of processes even if this happens during the work in the process itself. This is addressed in two ways. First, process workspaces can be adapted arbitrarily within the limits of typedefinitions stored within them. Second, both process descriptions and running processes are HOPLa programs. This means that a running process can be stopped, arbitrarily modified (through editing of the program text) and continued whenever exceptions make this necessary and without the loss of any data that had already been produced.