SEVESEO IS uses a client-server architecture:
The client application – the SEVESEO IS Viewer – is a Java Webstart application that is loaded from within a platform independent internet browser window. All instances of the Java client application communicate with the Seveseo server. This server is responsible, amongst other things, for applying user right restrictions, for efficient access to the database, for rendering maps and manipulation disaster management data.
The data are centrally stored in a relational database management system. An integration layer on the server side passes queries coming from the client software to the database. The client software communicates through HTTP (TCP) with the integration layer. For this, the integration layer is embedded in an Application Server. It also performs system tasks such as optimizing retrieval of data from the database and caching map data. Furthermore, it can integrate map data from remote Web Map Services (WMS). One server installation can serve multiple client applications simultaneously.
The server is also responsible for the integration of and communication with dispersion models. SEVESEO IS is requested to integrate arbitrary dispersion models. As the dispersion models to be integrated are not yet known, the means to transfer information between SEVESEO IS and the dispersion model must be independent of the applications.
Communication is based on a well-defined Web Service protocol (WSDL). If a user chooses to execute a scenario, SEVESEO IS requests the list of parameters that have to be specified for the invoked model. The Dispersion
Modelling Web Service sends this parameter list, and the SEVESEO IS Viewer uses the list to generate a user interface allowing the user to enter all parameters. The user then confirms the entry which sends a request to the Web Service to execute the model. The output is sent back through the Web Service Interface to SEVESEO IS. The results are stored in the database together with all other information concerning the scenario, and the results can be displayed on arbitrary maps. Every Web Service that conforms to the WSDL can be added to Seveseo.