Representation and Analysis of System Behavior Using Monotonic Signals

NASA has developed a new method for analyzing complex system behavior that also may be viewed as a type of data visualization and decision support tool. Large complex control systems may have thousands or even millions of sensors, each providing some type of signal that ultimately integrates into a larger organization. For each signal, behavior is represented by a sequence of pairs, with each pair containing a change value (monotonic) and a time interval length over which each of these changes occurs. Signal amplitudes and first derivatives serve as markers for these time intervals. This approach permits a finer scale characterization of the signal(s). The novelty of this approach is in using human visual interpretation in combination with computer signal analysis to monitor the behavior of complex systems in an enhanced manner.