Hierarchical Approach to Dependability Analysis of Information Systems by Modeling and Simulation

The paper presents a method of analyzing functionality aspects of complex information systems. The system analysis is based on integrating different computer system models, the networked systems and applications model, clients behavior model and collaboration between services in the analyzed system, into one coherent functionality based view suitable for system simulation. Modeling process incorporates hierarchical approach, i.e. the system is decomposed into groups of hosts and therefore groups of services, called molecules. The model is described in design by authors XML Domain Modeling Language (XDML). The integrated model is automatically transformed into an input file for modified SSFNet simulator. Additional information on input models could be read from other models or the user could play with all parameters of the XDML model. The paper presents developed software which implements described methodology and results of analysis for an exemplar information system.