“…Specifically, Zeroual et al (2017) looked at the residuals from such a model, smoothing them using an exponentially weighted moving average and then applied statistical tests to determine when to raise congestion alarms. The same model was considered in Abdelhafid et al (2018), where instead of a moving average, the authors considered upper and lower control limits for model residuals defined as three standard deviations away from some mean value. The authors again considered a similar approach in Harrou et al (2018), however using a generalized likelihood ratio test for determining if residuals belonged to one of two possible generating distributions.…”