Vortex : A Declarative Workflow Model

            Rick Hull and Francois Llirbat
                  Bell Labs

      In this talk, we present "Vortex" a new programming paradigm for
specifying a wide range of decision-making activities including
workflows. In particular we concentrate on "object-focused" workflows,
i.e., workflows focused on how individual input objects should be
processed within an organization.  Such workflows arise commonly in
practice, including insurance claims processing, and many electronic
commerce applications, and in the area of Customer Care, e.g.,
web-based storefronts.
      There are to primary goals for the Vortex effort: First, we want to
make it easy for non-programmers (e.g., business managers) to
comprehend and specify workflows. Second, we want to minimize the
response time for the execution of such workflow processes.  The first
goal is achieved by making Vortex paradigm fundamentally declarative
and by providing a variety of special-purpose constructs that help the
user to express decisions. The second goal is achieved by providing a
flexible execution model for Vortex that permits maximally eager and
parallel execution of the external processes.
      In this talk we first present and illustrate the core
declarative aspects of the Vortex paradigm. We then present the Vortex
execution model and discuss some optimizations and execution
strategies.