This paper presents the architecture of an enterprise service bus used in the construction of information systems processing large amounts of data for decision-making needs at the City Hall in Gdansk. The first part presents the key processes of bus development: installation of developing environment, database connection, flow mechanisms and data presentation. Developing processes were supported by models such as KPI (Key Processes Identifier) and SOP (Simple Operating Procedures) (also connected to the bus). The summary indicates problems in bus construction, especially processes such as routing, conversion, and handling of events.