The Criticality Assessment Manager interface consists of a Valve Criticality Modeling (VCM) module that assesses valves in two modes; one is based on model elements; the other is based on GIS layer elements. In the Based on Model Elements mode, only the valves in the model (usually system valves) are taken into consideration. In the Based on GIS Layer Elements mode, the valves under consideration can be those stored in a GIS layer (usually line valves).