Total Productive Maintenance

Part 5: Train Operations and Maintenance Personnel

by Roger A.P. Fielding, BENCHMARKS

As we discussed in the last article, “Schedule Maintenance,” the initial impact of TPM will be to increase the workload placed on maintenance personnel. The equipment inspections undertaken by the operators will identify maintenance and repair work that would otherwise have been overlooked or “put off” for another day. And, there will be demands for additional engineering and maintenance support from operators who are gaining new insights into the operation of their equipment. The frequency of equipment breakdowns will not immediately decline, and there will be a new urgency to get things fixed. The activities of the maintenance department will have to be coordinated with the autonomous maintenance activities of the operators.

A company implementing TPM must invest in training to ensure that the operators and maintenance personnel can manage their equipment properly. Operators must be trained in maintenance procedures, and their traditional operating skills must be improved. The maintenance personnel must be trained to attain a higher level of predictive and preventative maintenance.

In the context of the extrusion plant, operators should understand the relationship between the condition of the extrusion press and ancillary equipment—billet furnace, die ovens, and handling systems—and their performance measured in terms of productivity and recovery. Maintenance personnel must understand the factors affecting the control of the extrusion process and the sources of extrusion defects—twisting, waving, bowing, scratches, dents, etc. They must maintain the press and ancillary equipment so as to prevent the onset of these problems.

Through TPM, all associated with the extrusion operations attain a higher level of understanding of the extrusion process and the factors affecting it. All gain an improved insight into the operation of the extrusion press and its ancillary equipment. The press operators become the nurses, attending to daily inspections and making simple repairs. The maintenance personnel are like doctors, conducting exhaustive examinations, planning, scheduling and executing improvements and major repairs.

As was discussed in the previous article, scheduled maintenance will minimize breakdowns while meeting a company’s objectives for increased equipment availability and reduced maintenance costs. In order to minimize disruption during the introduction of TPM, scheduled maintenance, with features to allow for coordination of maintenance activities with the autonomous maintenance by operators, is introduced first. The results of planned maintenance activities are then audited, compared with the objectives, and corrected accordingly.

The introduction of TPM will result in extending the Mean Time Between Failures of equipment. Reducing the number of stoppages results in smoother operations and higher output. But, initially, the length of each breakdown might be expected to increase. This will change with time, and over time, and ultimately the time between failures will be extended without major increases in the time to repair. In the example cited in my 1998 Light Metal Age article on Japan, the Mean Time Between Failures was increased from 5 days to 20 days, while the Mean Time To Repair was virtually unchanged at about one hour per repair. (1)

The TPM improvement process is continuous, and the actions of the workforce continuously change to meet the challenges of improving operations: Improvement activities are planned, the plan is executed, the results evaluated, and a new list of actions identified.

(1) Fielding, Roger A. P., “The Japanese Aluminum Extrusion Industry,” Light Metal Age 56, nos. 5, 6 (June 1998): 6-19.

Total Productive Maintenance - Part 6