In the ever more competitive marketplace, manufacturing companies are under relentless pressure to increase profit margins, improve market shares and expand product portfolios while ensuring low-cost production, enabling a highly agile supply chain and serving a global market. These aren’t trivial challenges, and every company deals with them in unique ways. Companies constantly look for best practices and new management philosophies that can help meet these challenges and leapfrog the competition.
During the past decade, lean concepts, cellular manufacturing and quality circles have been on the forefront of management philosophies and practices that have helped companies face these challenges. In addition to these well-known concepts, there also is a practical concept, relatively undersold in the Western world, that has been practiced for a long time by many Japanese and Asian companies. It offers a sure-shot method to achieve overall lifetime manufacturing cost reduction with increased efficiencies in quality and reliability. It’s called total productive maintenance (TPM).
TPM combines the age-old American principle of preventive maintenance with Japanese concepts of total quality management (TQM) and total employee involvement to revolutionize how manufacturing facilities address machine and office maintenance. It’s built on the principles of empowering people at every level, fostering a sense of community ownership in operations as well as extending the reach of TQM, 5S (a Japanese system of organizing the workplace) and visual factory concepts.
TPM’s goal is to achieve zero breakdowns, zero accidents and zero errors. It fundamentally shifts the maintenance responsibility from maintenance departments to shop-floor production departments. While traditional maintenance programs have centered on machine maintenance, TPM encompasses the entire gamut of operations in the plant, including those of administrative departments and support departments, to achieve system-wide effectiveness.
How it works
TPM defines eight broad areas, called the pillars, each focusing on achieving the zero breakdowns, zero accidents and zero errors:
- Autonomous maintenance (jishu hozen)
- Continuous improvement (kaizen)
- Planned maintenance
- Early equipment management
- Quality maintenance
- Office TPM
- Safety, health and environment
Each pillar focuses on a specific set of activities and tasks. For the purposes of this article, I’ll zero in on autonomous maintenance and planned maintenance. Both concepts can be implemented and sustained with relatively low cost and, at the same time, give a marked increase in productivity through reduced downtime.
Also called jishu hozen, autonomous maintenance involves a seven-step process for achieving operator-controlled maintenance. This empowers operators (who usually have the most knowledge of their equipment) to perform day-to-day maintenance activities. This reduces shop-floor dependence on the maintenance department to perform routine maintenance activities. It produces a win-win situation for both the operators and the maintenance technicians. The operators take pride in ownership of their equipment, with which they are intimately familiar. The maintenance department can concentrate on planned maintenance programs.
The seven steps in the autonomous maintenance pillar are:
- Initial cleaning
- Eliminate maintenance hurdles
- Develop provisional standards
- General inspection
- Autonomous inspection
- Autonomous management
Before any of these steps are started on the shop floor, operators, supervisors, and production and maintenance managers should be educated on the concepts of TPM and given the reasons why the plant is undertaking this program, as well as complete management involvement and support for these activities.
Initial cleaning: Although this is basic and in some ways, just common sense, it’s often overlooked in day-to-day operations when no time is invested in the initial cleaning activity. In this process, specific machines are targeted and a date established for performing this activity. On that date, shop floor employees begin a comprehensive cleaning of the targeted machine with assistance from the maintenance department. They remove dust, stains, grease and oil from around the machine. A comprehensive color-coded tagging process identifies loose and leaky parts, worn out components, unsafe equipment shields, faulty hydraulic and pneumatic lines, etc.
The colors indicate which tasks can be performed by the equipment operator, and which need the assistance of maintenance personnel. Inaccessible areas of the machine that are critical to its functioning get tagged for corrective action to make these areas more accessible to operators. After tagging has been completed, perform the indicated corrective work. After the initial issues have been fixed, run the machine on a trial basis to ensure that the problems have been resolved. Some companies paint their machines white after the initial cleaning has been completed so that any new oil leaks, stains and dust become more visible to the operator and quick remedial measures can be taken.
Eliminate maintenance hurdles: This step is essential to sustain autonomous maintenance among operators. Make any inaccessible machine region that is important to the maintenance process more accessible, thereby ensuring that operators can perform their maintenance tasks in a safe and painless manner. Access to points of lubrication and fuses, easy-to-remove shields for cleaning, providing scrap metal collector bins all assist in making machines much more maintenance-friendly for the operators.