From Pipes-and-Filters to Workflows

Abstract

The Pipes-and-Filters (PaF) Architecture has been prominently exploited in the context of Enterprise Application Integration (EAI). The individual tasks have typically been implemented using specialized EAI-vendor technology, message flows, and quite often customer-specific implementations. This implementation approach is in conflict with flow technology, a cornerstone of the Service-Oriented Architecture (SOA). We show in this paper how this conflict can be resolved. We first show how the PaF architecture can be implemented using flow technology by transforming the appropriate PaF patterns, in particular those used in EAI, into appropriate WS-BPEL constructs. We then present the results of appropriate tests that show that the performance of the corresponding workflows is superior to the mapping of PaF patterns to message flows. We finish off with outlining the additional tangible and non-tangible benefits that the Workflow Management System (WfMS) provides, such as monitoring and process instance management. In a nut shell, we illustrate that the PaF architecture does not require an own implementation. It is sufficient to have a PaF modeling tool and then convert the appropriate models to workflows for execution by an appropriate WfMS.