Cybok, DieterKnop, Jan vonHaverkamp, WilhelmJessen, Eike2019-10-112019-10-1120043-88579-384-9https://dl.gi.de/handle/20.500.12116/28583In this paper we propose a Grid Workflow Infrastructure, which serves as the base for specifying and executing collaborative interactive workflows within computational grids. The infrastructure is based on the Open Grid Services Architecture (OGSA) and leverages the concepts of the Business Process Execution Language for Web Services (BPEL4WS). Using OGSA enables us to exploit advanced Grid features such as factories, lifecycle management and notifications. Leveraging BPEL4WS to a Grid enabled workflow language has the advantage that basic workflow functionalities, which are similar for Grid and Web Services, do not have to be developed again. The result is a state of the art Grid Workflow Infrastructure that was developed within a relatively short period. The main building blocks of the infrastructure are the specification of the Grid Workflow Execution Language (GWEL) notation and the implementation of a Grid workflow execution engine, using Globus Toolkit 3 (GT3) technology, for processing e-Science specific workflows specified in GWEL documents. The workflow engine itself is a high-level Grid Service, hence automatically Grid aware, that can be used within any GT3 environment.enText/Conference Paper1617-5468