38 Existing Parallel and Distributed Systems, Challenges, and Solut ions
1. Business processing in which tasks can be performed by various services
offered on the market by various providers on different terms. Busi-
ness workflows are more about control flow rather than processing large
amounts of data; various control mechanisms should be predicted in-
cluding exceptions.
2. Scientific computing in which workflow tasks are usually to process large
amounts data; parallel paths of the workflow can be used in order to
parallelize processing; control flow is rather simple.
3. Ubiquitous computing in which the graph depicts sequences of invo-
cations of services based on the context, i.e., a set of conditions that
initiates a given service or services.
Workflow