Systems reliability is usually an integral part of the curriculum for industrial engineering students. Very often, teachers limit themselves to a theoretical approach or simple calculations. Indeed, dedicated software is either expensive or complex for the intended use. Through this article, the objective is to teach students to create, by themselves, simple but adapted calculation tools from simple models given in a spreadsheet given in parallel with this article, allowing them to apply the theoretical knowledge acquired in the field of reliability. They will be able to easily understand the calculation of reliability thanks to the method of the functional diagram of reliability. Autonomously, they will be able to model most of the systems they might encounter in their engineering career. The developed tool will allow students to calculate the reliability of series systems, parallel systems, mixed systems, $k$-out-of- $n$ systems, bridge systems and other complex models using the method of decomposition or the event space method. In the end, not only will readers be able to carry out the practical work proposed in this article, but the autonomy and skills they will have developed will allow them to model any industrial system or device in the way they deem appropriate.