Three years ago an investigative report compiled by the Canada Centre for Mineral and Energy Technology (canmet) confirmed what many in the mining industry had suspected: that maintenance costs constitute an abnormally high percentage of to tal operating costs and that little was being done to effectively bring them und er control. Published in November, 1983, the 260-page A Review of Mine Maintenan ce in Canada was based on field visits to 12 mining companies, which accounted f or 10% of Canadian mines and more than 10% of mine production. The study was ins tigated, in part, by the mining industry.
Here is an abridged list of some of the report’s major discoveries:
* Maintenance costs range between 35% and 55% of operating costs.
* Only 16% of the respondents reported top management involvement in the implementation of maintenance management programs.
* Greater front-line management involvement was reported, but many supervisors and administrators also reported dissatisfaction with their involvement.
* Workers were seldom, if ever, involved in either the planning or implementation of maintenance programs.
* 84% of the programs were found to be poorly implemented.
* Most companies use computers as a data library. But once the information goes in, it isn’t used enough to justify its input.
* Only two of the 12 participants claimed any control of their maintenance function; and in both cases it was rated between 55% and 65% by the users. Other co mpanies claimed some form of systematic maintenance but not maintenance control.
* Many companies made a monthly maintenance report, but little attention is paid to the report. Sixteen per cent made a separate annual maintenance report as part of the over-all operation’s annual report. (However, it would have taken an astute maintenance executive considerable time to extract any meaningful data from it). The joint presentation of production and maintenance data encourages th e production-biased executive to disregard the maintenance information.
* Some managers, especially at the executive level, still believe in crisis- oriented maintenance management. This attitude guarantees not only high maintenan ce costs but also that the function will be unable to meet demands in the work p lace.
* Most participants agreed that effective planning and scheduling is needed to provide the base for proper maintenance. Most of the planning is done by the maintenance foreman. The planner performs mostly clerical functions. Very few plan ners actually engineer the work order.
* The report concluded that there was a need to develop better attitudes and skills in mine maintenance at all levels.
Members of the mining community may have been shocked at the critical tone of many of the comments in the canmet report, but they should not have been surpr ised. The growing increase in maintenance costs and its effect on total operatin g costs have long been known and discussed throughout the mining industry. Tradi tionally, individual mining operations have handled the administration of mainte nance as they have seen fit and maintenance management’s place in the organizati on has varied considerably in different operations. Since the report was publish ed, a number of operations across the country have developed well-executed maint enance programs. Attempts have been made to reach the proper balance where plant and equipment are not over-maintained or, at the other extreme, pushed beyond reasonable endurance. As a result, some exciting improvements in production tons per manshift and maintenance costs per ton have been reported. Maintenance Costs
Maintenance costs stem from materials and labor. An analysis of these can highlight problems and indicate new and possibly better ways to control costs.
* Materials — For all operations, the quantity of materials used is directly related to plant throughput. After initial start-up or a major extension or redu ction of the facilities, changes in the materials stabilize as the operation mee ts its production target. The quantity of materials required depends on the age of the plant and equipment, the duty they perform and the philosophy of operatio ns (i.e. whether the plant is pushed to the limit or not). There is little scope for cost reduction by maintenance people here.
* Labor — The productive time of a maintenance shift can be broken down into three classifications: travel, hands-on work and job preparation. Travel is gett ing to and from work sites. Some money can be saved by organizing routes and typ es of conveyances. But, on the average, there is little potential for cost reduc tion here.
In hands-on installation, downtime can be reduced by improved working aids and procedures; and there is scope to speed up the placement of material in equipme nt. There is room for cost reduction here.
Job preparation includes: receiving job instructions; planning and requisitioning materials; collecting tools and working aids; arranging for equipment shutdo wn and lockout; and cleaning up the worksite. It is the lack of control of job p reparation time that significantly increases maintenance costs. Maintenance Performance
Maintenance lacks a simple, objective measurement that can be used to determine when maintenance is under control and when it is not. Such a measure of perfor mance should apply to every operation and be understandable to everyone from hea d office to the worker in the field.
The cost per hour of the hands-on time that keeps the plant and equipment serviced and repaired conveys two messages: the degree to which mainten ance is produ ctive and its true cost. The effective time in reducing the workload is arrived at by combining the travel time to and from the job sites with the hands-on time. True Cost of Effective Time
In each working day there is non- productive time spent on lunch and coffee breaks; socializing and washroom visits; job preparation; and effective time. (See the table shown above). Allowing for vacation, some illness, statutory holidays and five days for safety and training, there are 225 working days (1,800 hours) for which the tradesperson is paid annually. No overtime allowance is made. The annual cost of a tradesperson is $48,000, to the nearest $1,000, based on company fringe benefits of 40%, overhead for supervision and administrative support of 20% and an hourly base rate of $16. In other words each working day costs $215. This is the figure which, when divided by the effective hours in the shift, gives the measure of maintenance productivity. Referring to the example s shown in the table (Shift Breakdown Patterns), the average cost ranges from $35.35 to $62.85. Costs soar when the effective time of the tradesperson is not controlled. Every effort must be made to reduce the time spent by the tradesperson on job pre paration.
The amount of job preparation varies with different categories of work, just as the tendency to pass on some of the responsibility for it varies from job to j ob. In either situation, the greater the percentage the job preparation is to ef fective time, the more likelihood there is to be loss of effective time. Categories of Work
Maintenance functions can be broken down into the following categories:
* Preventative maintenance is routine, scheduled equipment inspection, lubrication, servicing, cleaning and non-destructive testing. (Loss of effective time s hould be minor).
* Scheduled maintenance is major work of sufficient scope and importance that it must be scheduled with production supervision. (Loss of effective time should be minor).
* Unscheduled repair covers the tasks that can be completed in 2-3 days with no danger of equipment failure. Tasks are normally one- or 2-person jobs that can be completed in two or fewer hours. Loss of effective time depends on the demands placed on the first-line maintenance foreman. (The percent of job preparation time to effective time is likely to be high).
* Emergency repair covers the tasks that must be performed immediately because, if not accomplished,
they could result in injuries, significant production los s or further equipment damage. The foreman must take workers from other jobs and assign them to emergency work as it arises. (This creates additional loss of effective time; otherwise it has an outcome similar to unscheduled repair). Maintenance System
All requests for maintenance work should be written. The instructions should tell the tradesperson exactly what is to be done and where the time used should b e charged when he fills out the timesheet at the end of the shift. Control of th e work requires differentiation of repetitive and non- repetitive work which can be scheduled a week in advance as well as running repairs which come up at the last minute and which have to be completed between now and the next three days.
As the name implies, repetitive maintenance is carried out at predetermined (usually fixed) intervals, with the sole aim of preventing failure. It includes i tem replacement and repair, fixed or continuous inspection and lubrication. The actions, frequencies and resources can be planned to produce a predictable workl oad. It normally uses 10%-30% of the labor resources. Priority for repetitive wo rk is highest after emergency running repairs.
Non-repetitive work involves major overhauls and plant and equipment improvement or replacement, which are inevitable with today’s acceleration in technologic al advancement. The need for maintenance is identified mostly during inspections. The urgency to complete it varies and it is scheduled from one week to months in advance. It has the lowest priority, receiving attention after non-emergency running repairs. Depending on the operating philosophy, it can use the barest mi nimum to 30% of available labor. If the highest-priority non- repetitive work is left undone, it then demands emergency treatment and the resulting unscheduled downtime creates havoc with operating performance.
Running repairs are constantly required (mainly quick-fix jobs of a couple of hours for one or two people). Emergency treatment is given to safety hazards wit h a high potential for causing injury or when production has been interrupted or reduced. These are top priority, done before anything else. The remainder of these last-minute jobs are to prevent an emergency situation from occurring, often covering the interim until a permanent repair can be scheduled.
Running repairs are unpredictable and cannot be scheduled, but allowance has to be made for them in the maintenance schedule. This varies from 40%-80%. Planning and Scheduling
Jobs not requiring equipment shutdown can be performed without approval from production. All other planned jobs are scheduled to fit into the production plan. The most critical are those which require an interruption in production or essential services. Scheduling centres around the basic resources:
* Equipment — The equipment on which the work is to be performed must be made available at the best time for all concerned. It must be made available long en ough to get the job done.
* Materials — The necessary repair materials must be on hand or the job can’t be attempted.
* Maintenance Labor — The right skills at the best time and in the proper quantity.
Once a schedule has been approved by production, there exists a contract between maintenance and production so that they will comply with that schedule. In ef fect maintenance has agreed to perform the work while production has agreed to m ake available the equipment. This happens at a weekly maintenance schedule meeti ng, which is vital to maintenance management. At the same meeting compliance to the previous week’s schedule is reviewed and the proposed corrections assessed. Priorities are set for new non-repetitive work orders. Backlog
The backlog is the planned, non- repetitive work scheduled for completion over a consistent time-span in the order of four to 12 weeks. An accurate balancing of the work force to the workload can only be done when the load is known. A ste ady complement can be maintained if the load is steady. The only part of the loa d which is steady is repetitive work. Non-repetitive work performed after runnin g repairs will fluctuate. Sometimes this is because of absenteeism in the mainte nance crew or because of overtime.
If equilibrium in the workforce is to be maintained, then non-repetitive work, running repairs, absenteeism and overtime must also be in equilibrium. To reduce the backlog (the non-repetitive work) or to keep it stable, it is essential to complete sufficient scheduled work continuously. When work on running repairs displaces scheduled work, the backlog goes up.
There is no set, correct level of backlog. The result depends on a good work order system, careful estimating of labor and an effective planning activity. System Network
However large the operation, the basis for control by each crew will be as shown by the network diagram on page 15. While the planners’ prime responsibility i s the control of repetitive and non-repetitive work, they assist the first-line foremen daily in the work preparation of the running repairs (especially in mate rial acquisition). Operators know their equipment well. They are prepared to tel l maintenance personnel about many suspect problems; they are an excellent sourc e of information on equipment condition; they can also check lubrication and oil levels, test hydraulic controls and verify safety devices. Often they are able to carry out daily lubrication services when it is difficult for regular lubrica tion personnel to reach the equipment.
Today any size of maintenance department can afford a computerized system. Used properly, it will pay for itself in less than a year. It can reduce the amount of paperwork, be simple to use and be understood by all. Pertinent information can be readily available for the making of decisions. Monthly Maintenance Report
The monthly report provides assurance that results being achieved conform to the work plan or, if the information is divergent from the plan, what remedial ac tion is being taken. Presentation must be timely. With early warning, variances can be acted on as opposed to reacted to. There should be a minimum of supportin g text. Poring over voluminous boiler plate is a waste of time.
Performance by maintenance can be judged by the following criteria:
* material and labor costs — actual, budgeted and forecast;
* unscheduled plant or area shutdown caused by equipment or plant
malfunction;
* completion of major jobs;
* major jobs that were unscheduled with an explanation for the reason;
* trend of percentage of scheduled work;
* trend of effective hours per shift and the cost per hour;
* trend of backlog in weeks; and
* trend of overtime.
A company’s attitude to maintenance is reflected in its monthly report. Keith Bowley is a Toronto-based maintenance management consultant. This, his first article for The Northern Miner Magazine, will be followed by a semi- regular column on how to run an effective maintenance department.
Bowley has wide-ranging experience in the mining industry, having recently designed the maintenance system for Noranda’s Mattabi mine. Previous to that, he w as contract administrator with Denison Mines on its Cloverhill potash project. H e has also worked with Kilborn Ltd. in South Africa and on the Quintette Coal pr oject; as manager of engineering for Tara Mines in Ireland; as mechanical and el ectrical project engineer with Newmont Mining on the Granduc copper mine; and as plant superintendent for Rio Algom’s Milliken Division in Elliot Lake.
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