Maintenance AVOIDING CRISES

Increasingly, high costs for maintenance must be brought under control. Maintenance can be made more effective and affordable if running repairs are controlled. Running repairs refer to quick-fix jobs that crop up unexpectedly from time to time.

Mines have innumerable components of plant and equipment. As they gradually deteriorate it is impossible to anticipate the defects and breakdowns. However, many of these problems are eliminated by preventive routines identified through analysis. Improved equipment availability and steadier maintenance workflow are the result. Repair work is best and fastest when carried out in controlled environments. Also, job preparation becomes more efficient and much less time-consuming. Job preparation includes receiving job instructions; planning and requisitioning materials; collecting tools and working aids; arranging for equipment shutdown and lockout; and cleaning up the worksite.

The first step in compiling a maintenance history for analysis is to number each critical piece of equipment or major component and keep source documents and technical specifications on record. Equipment repairs should be recorded as they occur. Data can later be retrieved in the form most useful for the particular analysis being made. Information on equipment should be collected until such time as the pieces of equipment are replaced through preventive routines.

Computers render the handling of historical data relatively simple. With the computer’s memory capacity, storage of data is almost unlimited. The problem is deciding which records should be collected.

The effectiveness of maintenance depends on co-operative interaction between maintenance personnel and those from production, warehousing, purchasing and accounting. However, the maintenance department should not keep records that don’t directly relate to maintenance. Costs that are not directly related to maintenance tend to distort, or overstate, the “true” cost of maintenance.

Analysis can provide proof of safety and other statutory work. It can assess maintenance performance, material usage, effectiveness of preventive and predictive maintenance programs, estimated versus actual costs, and breakdown frequencies. It may be necessary to shorten inspection periods to more accurately predict problems, or intervals between servicing may be extended without impinging on machine performance. Evaluations can be made to determine how costs have been affected by substitution or redesign of equipment. Tires are a perfect example. Competition in the tire industry means that new models are constantly developed. Maintenance personnel must keep abreast of these developments so as not to miss any improvements which might affect availability and cost of materials.

The first-line maintenance foremen and their crews know where revision in plant and equipment is required, yet they are usually not formally consulted. With a brief period allocated each week for analysis, they could collectively review problems and suggest solutions. The participation and recognition would encourage interest in better maintenance.

History-and-analysis is an essential tool for maintenance management. Plant and equipment availability increases because the causes of unscheduled shutdowns are identified and routines are established to prevent their recurrence. The establishment of new routines should be a high priority. The more critical items of plant and equipment should be treated first.

Repair orders should be collected only long enough to determine the cause of a problem and, if necessary, to monitor the result of the correction. Sometimes the cause of a problem is obvious and a record is needed to s ee how equipment compares with substitutes. All new routines must be approved by the production department. Keith Bowley is a Toronto-based maintenance consultant.

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