This paper presents an automated mechanism, processes and workflow for the seamless integration of distributed geographical information services for the creation of an automated data processing service, known as a geoprocessing service. It describes generic principles for designing and developing real-time geoprocessing services and covers key aspects of seamless service integration and design for an automated geoprocessing service. These include brief descriptions of a `total object-oriented' approach, unified national adoption of the Open GIS Consortium's operational framework and specifications, implementation of standardised coding systems for geo-referenced data, design for service application interfaces, geodata fusion of assured integrity and quality and automation of data processing for service delivery. Automation is achieved by programmatically utilising modular software resources in compliance with the Component Object Model. This paper draws on a proven approach of relevance to specialists working in similar areas related to the design and development of Internet-based geoinformation service systems.