Lesson 5: Maintenance systems

In this lesson, we will explore different maintenance systems used to ensure the availability of machinery and equipment, including on-demand maintenance, planned preventive maintenance, maintenance based on technical condition testing, Total Productive Maintenance (TPM), and Reliability Centered Maintenance (RCM).


  • The reliability and availability of machinery, equipment, and components are crucial in various industries.
  • The choice of maintenance system depends on factors like repairability, the consequences of failure, and available technological options.
  • Let’s delve into different maintenance systems that organizations employ to ensure smooth operations and minimize downtime.

On-Demand Maintenance and Repair

  • In this system, repairs are carried out only after a failure has occurred.
  • Failed components or parts are repaired or replaced when needed, along with regular care and lubrication operations.
  • Advantages: Certain components can be used to their wear limits.
  • Disadvantages: Unplanned intervention leads to longer downtime, and immediate replacement isn’t always possible.

Planned Preventive Maintenance (PPM)

  • PPM focuses on preventing faults and eliminating unexpected failures.
  • Common in industries, it involves scheduled inspections and repairs based on a predefined cycle schedule.
  • Maintenance activities during PPM include regular inspections, adjustments, and significant repairs.
  • The goal is to maintain machinery and equipment in optimal working condition and prevent unexpected failures.

Preventive Maintenance Based on Technical Condition Testing (Diagnostics)

  • Traditional preventive maintenance relies on analyzing component wear and logic laws.
  • However, complex factors can influence component service life, making wear analysis less accurate.
  • Diagnostics involve continuous or periodic instrumental condition tests during operation to determine the timing of maintenance and repair.
  • This approach considers uncertain factors like material quality, operating conditions, and handling of machinery.

Total Productive Maintenance (TPM)

  • TPM, originating in Japanese industry, emphasizes preventive maintenance involving all employees.
  • It began with adopting preventive maintenance from the USA and evolved into a holistic approach.
  • TPM includes elements like improving equipment utilization, introducing autonomous maintenance by operators, planned maintenance, training programs, and designing reliable and maintainable machinery.
  • It focuses on employee involvement and collaboration in maintaining equipment.


  • The choice of a maintenance system depends on the specific needs of an organization, including the nature of machinery, repairability, and operational consequences.
  • Maintenance systems aim to enhance machinery reliability, minimize downtime, and extend equipment life.
  • Organizations may adopt a combination of maintenance systems to meet their unique requirements.
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