A system analyzer and a method for analyzing an impact of a change in a component of a distributed control system (DCS) are disclosed. The system can collect and store data representing the DCS components and their interconnection as well as signals of the DCS components. The DCS can be graphically modeled with nodes and directed edges, wherein a node represents either a type of DCS component or a signal of a DCS components, and wherein an edge is an “influence”-edge, or a “contains”-edge. Information on a change of a DCS components is received, a depth first or breadth first search is performed over the “influence”-edges and “contains”-edges and determine unchanged DCS components which would be affected by a malfunction, a removal or a taking out of operation of the at least one DCS component, and information on the affected DCS components is transmitted to an operator interface.