Maintenance Workers, Machinery

• Oil can1860–1920

  Oil can and grease pot (pre-industrial-chemistry lubrication)

  The 19th-century factory oiler's entire kit fit in a leather satchel: a long-spout oil can for journal boxes and bearings, a grease pot and brush for slow-speed surfaces, cotton waste for wiping, and a schedule kept in the worker's own memory or on a handwritten card. The lubricants were crude by modern standards -- animal tallow, whale oil, and then mineral oil as Pennsylvania petroleum production ramped up after 1859. The oiler walked a defined route through the plant on each shift, touching every moving part on the checklist. There was no science to the intervals; experience and smell (hot metal, burning grease) were the primary diagnostic instruments. The job required physical access to every corner of the machine room, often in cramped, loud, and dangerous conditions.

• Engineered lubricants1920–1965

  Engineered lubricants and viscosity standards (ISO 1921; ASLE founding 1944)

  The 1920s brought the first petroleum-refining processes engineered specifically to improve lubricant performance, followed by additive chemistry in the 1930s and 1940s (antioxidants, corrosion inhibitors, viscosity improvers). The American Society of Lubrication Engineers was founded in Chicago on March 3, 1944, codifying lubrication practice as a professional discipline. For the factory oiler, this era transformed the work from informal topping-off to a specification-driven regime: each machine now had a data plate recommending a specific oil grade, a service interval, and a fill quantity. The International Brotherhood of Firemen and Oilers (AFL expanded the union's jurisdiction to include oilers in 1919; the IBFO name was formally adopted at the 1956 convention) gave these workers formal union standing and negotiated the job descriptions that separated lubrication workers from mechanics.

• Computerized Maintenance Management Sys…1965–1985

  Computerized Maintenance Management Systems (CMMS) -- IBM mainframe punch-card era to minicomputer era

  The first computerized maintenance management systems appeared in 1965 on IBM mainframe computers, using punch cards to record work orders. Initially available only to large manufacturers and government agencies, these systems formalized the lubrication route into a scheduled-work-order workflow: the system generated a work order, the worker completed the task, the completion was recorded. By the 1970s, computer terminals replaced punch cards; in the 1980s, the minicomputer brought CMMS within reach of medium-sized factories. For the machinery maintenance worker, CMMS was a mixed development: it made the job more systematic and the worker accountable by name to each completed task, but it also made the labor more measurable and therefore more auditable for efficiency gains. The 1970s effectiveness-questioning of preventive maintenance ("over-maintaining" critique) began shifting thinking toward condition-based triggers, planting the intellectual seeds of predictive maintenance.

• Total Productive Maintenance1971–1995

  Total Productive Maintenance (TPM) and route-based predictive maintenance

  In 1971 the Japanese Institute of Plant Maintenance awarded the first PM prize to Nippondenso (a Toyota supplier), formally recognizing Total Productive Maintenance as a management system. TPM, developed by Seiichi Nakajima between 1950 and 1970, redistributed maintenance accountability across the entire organization -- from dedicated lubrication workers to machine operators themselves, who were trained to do autonomous maintenance (cleaning, inspection, basic lubrication) on their own equipment. For the 49-9043 category, TPM had a dual effect: in Japanese-influenced factories adopting lean manufacturing, autonomous maintenance absorbed some routine lubrication tasks into the operator's job, reducing headcount of dedicated lubrication workers; in traditionally organized US factories, it raised awareness of systematic preventive maintenance without restructuring job roles. Route-based predictive maintenance (technicians physically touring machines with vibration meters and thermal cameras) became practical in the 1990s with portable instruments and route-based data collection software.

• PC-based CMMS1995–2015

  PC-based CMMS and Windows-era maintenance scheduling software

  Personal computers running DOS and then Windows placed CMMS software in virtually any factory office by the mid-1990s, and the internet made cloud-hosted CMMS accessible by the late 1990s. For the machinery maintenance worker, the PC-CMMS era meant a printed work-order sheet each morning (later a handheld device with a barcode scanner) and a strict close-out protocol: scan the equipment tag, scan your employee badge, enter the lubricant applied and the quantity, close the order. The CMMS now held a complete machine history, enabling analysis of which machines were consuming the most labor. This auditability accelerated the shift from time-based to condition-based intervals -- but the analytical capacity was still mostly in the hands of maintenance planners and engineers, not the worker on the floor. US manufacturing employment peaked in 1979 at 19.5 million and had fallen to 16.8 million by 1995, pulling the maintenance support workforce down with it.

  Effect on the work

  The PC-CMMS era coincided with the broader deindustrialization of the US manufacturing base. Between 1980 and 2000, the US lost approximately 2 million manufacturing jobs, and the 49-9043 workforce compressed accordingly from its estimated 1970s peak.

• Industrial IoT2015–present

  Industrial IoT and AI-driven predictive maintenance (IIoT/PdM era)

  The Industrial Internet of Things (IIoT) platform market, valued at $53.7 billion in 2022 and growing at 10.5% CAGR, has embedded real-time vibration, temperature, and acoustic sensors in industrial machinery at scale. These sensors feed machine-learning models that predict bearing failures, lubrication deficiencies, and seal degradation days or weeks before they would be detectable by a worker on a physical inspection route. For the 49-9043 maintenance worker, IIoT predictive maintenance is the most significant restructuring of the job since the shift from the oil can to the CMMS. The work is increasingly condition-triggered rather than schedule-triggered: instead of lubricating Bearing 14B every Monday because the schedule says so, the worker lubricates Bearing 14B when the system flags an anomaly in its vibration signature. This makes each intervention more purposeful but reduces the total number of interventions, compressing the headcount needed. The mainstream daily-driver tools in 2026 are cloud-hosted CMMS platforms (IBM Maximo, SAP PM, Limble, Fiix) integrated with IIoT sensor dashboards, paired with mobile work-order apps on ruggedized tablets or phones. AI is not replacing the worker on the floor -- the physical act of applying lubricant still requires a human -- but it is reducing the frequency of dispatching that worker, and routing more complex condition-based interventions to Industrial Machinery Mechanics (49-9041) rather than 49-9043 Maintenance Workers.

  Effect on the work

  Employment in 49-9043 fell from approximately 65,240 (May 2020) to 57,500 (May 2024) -- a decline of 12% in four years, accelerating a longer-term structural compression. BLS projects a further -2.8% decline by 2034, citing "predictive maintenance allows for more efficient scheduling of work activities for maintenance workers" as the primary driver.

What's changing in your day

Three parts of your work where AI is already doing real lifting, and what stays yours.