“…We adopted an ngram-based solution and a probabilistic model approach because sequence analysis approaches are widely used in practice. As matter of fact, there are several research studies adopting n-grams (or similar algorithms) and probabilistic models to perform run-time detection of anomalies up to now [87,88,89,90,91,92]. Moreover, we did not include more complex approaches, such as neural networks-based approaches, since they require massive data for training [81,93,94].…”