The invention provides an online anomaly monitoring and diagnosis method and
system. The method comprises the steps that the causal relation and conditional relation among all signals are defined based on a
directed graph model; based on definitions of the signals by the
directed graph model, the signals in acquired historical data are classified, and a
training set of the historical data is established to perform model training and determine
model parameters; and based on real-
time data theoretical values of the signals in real-
time data obtained after the real-
time data acquired through online monitoring is input into a trained model, whether the signals in the real-time data are abnormal is determined. The
system adopting the method and a computer readable medium storing a program executing the method are also included. Through the method, the
system and the computer readable medium, a complete logic relation and casual relation are constructed for the whole process of industrial production and operation through the
directed graph model, and more reasonable, more correct, more accurate and efficient production online anomaly diagnosis prediction is realized in combination with
machine learning.