The extrusion process of plastic transformation involves a series of variables and components which must be associated with the concept of reliability to achieve an expected performance in operational and quality terms. This paper describes the reliability framework of an extruder of a packaging company located in Brazil through the following mathematical representations: probability density function f(t), reliability curve R(t) and function rate of failure h(t). Through a statistical software and under the light of classical concepts of reliability analysis, the set of representations evidenced high probability of fault occurrence at the beginning of operating time, which was shown by the density function and the accumulated failure charts. Besides that, in the current operating conditions of the machine, approximately 50% of the failure observations happen on the hour 106 of operating time. It is expected that this work may act as a guide for future implementation of improvement activities.