System for securing a cyber-physical method

Industrial system comprising machines, systems for controlling machines connected by a first communication network and a gateway intended to connect the first communication network to a second communication network, the gateway comprising a memory and comprising a processor configured to copy to the memory first data transmitted over the second communication network and relating to the operation of the machines, further comprising an analyser, configured to:

• collect values of variables relating to the operation of the machines,
• determine, for at least some of the variables, ranges of values from at least one first operational model of the machines,
• detect at least one anomaly, if the value of at least one variable is outside of the range of values of said variable, said anomaly having a likelihood,
• detect, from the at least one anomaly, at least one undesirable event, to which is allocated an impact on the industrial system, said impact having a severity,
• determine, for each impact allocated to each of the at least one undesirable event, a likelihood, from a combination of likelihoods of the at least one anomaly detected,
• provide, for each impact and the severity-likelihood combination thereof, a numerical value,
• determine an overall risk level of the industrial system from the numerical values obtained of the impacts of the at least one undesirable event detected.