This contribution describes how disturbances in a control system can be isolated and diagnosed automatically based on plant topology. In order to demonstrate this, a prototype software has been designed and implemented which, when given an electronic process schematic of a plant and results from a data-driven analysis, allows the user to pose queries about the plant and to find root causes of plant-wide disturbances. This hybrid system puts together two new technologies: the plant topology information written in XML according to the computer aided engineering exchange (CAEX) schema and the results of a signal analysis tool called plant-wide disturbance analysis (PDA). The isolation and diagnosis of the root causes of plant-wide disturbances is enhanced when process connectivity is considered alongside the results of data-driven analysis. (c) 2006 Elsevier Ltd. All rights reserved.