**4.1 The input variable "vibration analysis"**

For the determination of each variable, it was convenient to divide them into strips to approximate the actual situation to be checked. The calculation of these ranges on a scale according to **Tables 6–12** is shown below.

As the first level of variation, "vibration level" in **Tables 6** and **7**, let us consider better variable levels that were subdivided into four variables, normal, permissive, alert, and critical, each corresponding to the classification of vibration, velocity, and displacement levels measured in the equipment.
