Control systems receive input signals to execute a process, resulting in an output. Based on this sequence, the computational tool has the function of detecting and diagnosing anomalies in the system. The oscillation diagnosis of the system is based on the analysis of the oscillations generated by any disturbance, whether internal or external. The most appropriate form of detection is through noninvasive methods, therefore, there are some specialized in system improvements such as; detection of peaks in the power spectrum (FFT), the method based on time domain criteria and the absolute error integral (IAE) and the method based on the autocovariance function (ACF). The computational tool aims to detect oscillations of closed-loop control systems, through the 'IAE', 'ACF' and 'FFT' method.