1. A computer-implemented method for predicting capacity of Information Technology (IT) system resources, the computer-implemented method comprising: performing an automatic execution of a Box and Jenkins method for forecasting a behavior of a dataset representing a capacity of resources of an IT system, wherein the performing includes: (a) pre-processing the dataset, including providing one or more missing values to the dataset, removing level discontinuities by detecting change points corresponding to level discontinuities in the dataset and detecting further level discontinuities using a two-step filter, the two-step filter including creating a vector of candidate jump points and computing seasonal analysis on the vector of candidate jump points to obtain the further level discontinuities, and removing outliers from the vector, and handling anomalies of the dataset by leaving out one or more last samples from the dataset; (b) obtaining a trend of the pre-processed dataset including identifying and filtering the trend out of the preprocessed dataset based on a coefficient of determination methodology to generate a detrended dataset; (c) obtaining a resulting stationary series by detecting seasonality from the detrended dataset using an auto correlation function of the dataset, detecting seasonality using the auto correlation function on an aggregate series of the dataset, and removing detected seasonality based on a seasonal differencing process; (d) modeling the resulting stationary series under an autoregressive-moving-average (ARMA) model; and predicting the behavior of the IT system resources based on execution of steps (b)-(d) in reverse order.