REFlex: An Efficient Web Service Orchestrator for Declarative Business Processes

Declarative business process modeling is a flexible approach to business process management in which participants can decide the order in which activities are performed. Business rules are employed to determine restrictions and obligations that must be satisfied during execution time. In this way, complex control-flows are simplified and participants have more flexibility to handle unpredicted situations. Current implementations of declarative business process engines focus only on manual activities. Automatic communication with external applications to exchange data and reuse functionality is barely supported. Such automation opportunities could be better exploited by a declarative engine that integrates with existing SOA technologies. In this paper, we introduce an engine that fills this gap. REFlex is an efficient, data-aware declarative web services orchestrator. It enables participants to call external web services to perform automated tasks. Different from related work, the REFlex algorithm does not depend on the generation of all reachable states, which makes it well suited to model large and complex business processes. Moreover, REFlex is capable of modeling data-dependent business rules, which provides unprecedent context awareness and modeling power to the declarative paradigm.