GiN: A graphical language and tool for defining itask workflows

Abstract

Workflow Management Systems (WFMSs) are software applications that coordinate business processes. The coordination is based on a workflow model, expressed in a domain-specific Workflow Description Language (WDL). WDLs are typically graphical languages because the specification has to be understandable for domain experts as well as workflow application developers. Commonly, only simple workflows can be described while additional coding is needed to turn the description into a running application. The iTask system is a combinator library, embedded in Clean, to construct WFMSs. Complex workflows can be defined declaratively from which a complete web-based application is generated. However, the textual specification is less suitable for domain experts who are used to graphical notations. In this paper we address this problem and present GiN: a graphical notation for iTask workflows, as well as a prototype implementation of a tool to construct GiN workflows interactively and graphically. The tool is fully integrated in the iTask system: it is just another iTask component, and workflows created with GiN can be subsequently added and executed dynamically as part of other workflows.