The use of system analysis and preventive maintenance in today’s industry becomes a necessity as it increases equipment availability. These methods reduce the frequency of failures. The objective of this article is to present a case study for improving the reliability and availability of a production group in an industrial enterprise. Next, we present an improvement in maintenance. Finally, we present and discuss the application of preventive maintenance. Through an industrial manufacturing model, we will combine three tools; SADT modelling, the FMECA analysis and the Pareto diagram to arrive at an optimal maintenance approach that will be a decision support tool in order to minimize the repair costs and the downtime of the system.