1. A system-monitoring method comprising: providing a state-vector self-organizing map containing units stored in an electronic memory; providing a moving-average self-organizing map aligned with the state-vector self-organizing map and containing elements stored in an electronic memory; and continuously generating a next set of metric values that defines a current state vector of a system, determining a best-matching unit of the state-vector self-organizing map for the current state vector, using the current state vector to update the best-matching unit and a neighborhood of the best-matching unit within the state-vector self-organizing map and elements of the moving-average self-organizing map corresponding to the best-matching unit and the neighborhood of the best-matching unit within the state-vector self-organizing map, and when a scalar value currently associated with the element of the moving-average self-organizing map corresponding to the best-matching unit within the state-vector self-organizing map is below a threshold value, storing an indication within an electronic memory that the system has likely entered an abnormal state.