3. Trends in Preventive Maintenance (1950–2025)

For more than seventy years, preventive maintenance has been a major pillar of modern industrial maintenance. While corrective maintenance dominated until the mid-20th century—as epitomized by the famous expression “If it ain’t broke, don’t fix it”—the increasing complexity of equipment, along with heightened demands for productivity and safety, has led companies to adopt effective methods to prevent failures from occurring. In this context, preventive maintenance has gradually become widespread among large, medium, and small businesses. This section presents the evolution of preventive maintenance tools and methods, aimed at early detection of equipment deterioration and at avoiding the consequences of failures. The organization and management of maintenance plans are not covered in this article; readers may refer to