Industry 4.0 is based on the internet of things, this means, that in industries or companies the value chain, including processes, products, hardware, and software, among others, exists the necessity to implement new knowledge technologies to implement and control Industry 4.0 interactions, in other words, with the advantages of industry 4.0 such as the used of real-time data, big data, blockchain, human-machine interaction, cyber-systems, among others, the electronic devices that allowed this interaction and electronic data interchange centralize, need to be in the highest possible reliability perform, aiming to be able to carry out all these activities safely and effectively. In this research, the objective is to introduce some general advantages of Industry 4.0 and how reliability engineering is an important ally in the performance of the functions of Industry 4.0. Then, this manuscript presents the necessary knowledge and applications of reliability engineering that can be implemented in Industry 4.0 as stress-strength analysis in the case of equal shape parameters β_(s= ) β_S ; stress-strength analysis β_(s ≠) β_S; Nonnormal capability index and Weibull Capability index, by using Weibull++ Software and mathematical procedure. Another target of this research is to demonstrate that by using reliability engineering it is possible to have better control in such a way that efficiency and productivity stay and even can increases. Also, reliability engineering represents security and stable processes. Finally, with the merging of Industry 4.0 and reliability engineering, the making decision process is more reliable decision-making.