Maintenance Benchmarking


Comparison of Maintenance KPI"s in the Australian Mining Sector

Maintenance Benchmarking Study in the Australian Mining Industry

 

 

 

 

 

 

 

 

An example of work that I have undertaken on behalf of mining clients in respect to maintenance benchmarking and analysis is provided below:

Ref

Maintenance Benchmark Survey – Underground Copper Mines in Australia

Mine A

Mine B

Mine C

Mine D

1 Number of underground mines

1

2

2

1

2 Number of open pits

0

0

1

0

3 Number of years in operation (yrs)

?

6-8

10-12

7

4 Purpose of maintenance To provide safe, reliable and cost effective operation of plant and equipment at mechanical availability levels required to deliver production throughput targets Maximum equipment and plant availability and reliability at the lowest cost To provide the necessary capacity for production at the lowest cost. Sustain a safe and efficient production of copper
5 Operational bottleneck location Tertiary/Quaternary Crushing Milling Mill Mining – introduction of clean and sized ore to the concentrator
6 Does the operational bottleneck influence maintenance priorities and if so how? Yes, frequency and duration of access is limited and major work is difficult to schedule Yes, prioritise response to breakdowns and management tend to push out major shuts when production priorities occur Yes, ensure all mill shuts are well planned and fully kitted before commencement Yes, in relation to mining activity reactive maintenance
7 % of annual capital expenditure related to replacement of equipment and plant

~5%

2 – 7%

3%

50%

8 Tonnage of saleable product produced

107,000

53,000

27,000

49,000

9 Tonnes of ore milled

2,412,000

1,600,000

500,000

2,290,000

10 Operational time (annual)

8,760

8,760

8,760

8,760

11 Maintenance  hours as a % of production man hours

76%

150%

105%

N/A

12 Estimated annual stores turnover

1.8

1.3

1.4

3.1

13 % of stores requests made which were able to be satisfied on request)

99%

80%

75%

70%

14 Estimated maintenance overtime

6%

5%

5%

6%

15 Estimated % of scheduled maintenance compliance

85%

80%

60%

70%

16 maintenance costs as a percentage of C1 operating costs

35%

45%

40%

26%

17 Employee labour/contractor maintenance costs as a % of annual maintenance expenditure

27%

24%

40%

31%

18 Contractor labour maintenance costs as a % of annual maintenance expenditure

16%

14%

0

19 Total labour maintenance costs as a % of annual maintenance expenditure

43%

38%

40%

31%

20 Spares and repairable expenditure as a % of annual maintenance expenditure

38%

42%

36%

?

21 Mobile Fleet availability

78%

82%

80%

22 Haul Trucks

83%

82%

23 Boggers

74%

24 Jumbos, solos, Cabolter

77%

25 Underground crushing & conveying

80%

79%

82%

78%

26 Surface Crushing & Conveying

88%

88%

27 Backfill

88%

28 Auxiliary Equipment

79%

29 Total
30
31 Processing

96%

93%

88%

32 Grinding

89%

33 Reagents & Flotation
34 Concentrate Thickening
35 Filtration

88%

36 Tails Thickening
37 Total
38 Maintenance strategy
39 Number of maintainable equipment items

740

1000

560

4606

40 Number of maintainable equipment items with a valid documented maintenance strategy

430

220

150

889

41
42 % of maintenance strategies using an assigned ‘run to failure’ maintenance strategy

20%

10%

10%

0%

43 % of maintenance strategies using preventative maintenance practices

50%

90%

80%

98%

44 % of maintenance strategies using predictive maintenance practices

30%

0%

10%

2%

45 % of maintenance strategies using proactive maintenance practices

0%

0%

0%

0%

46
47 Total

100%

100%

100%

100%

 

Ref

Notes

4 It is generally a positive outcome that the purpose of maintenance focuses  on production but the purpose could be made clearer by recognises that it is saleable copper and not other intermediary products (mined ore, crushed ore) that matter. There is also a potentially unintended consequence resulting from the reference to ‘production targets’. What if the targeting process is flawed or where there is capacity in excess of the production targets or that the equipment is not capable of meeting the target availability and reliability? . How does this purpose statement guide maintenance then?  These questions naturally guide you to the conclusion that maintenance need to think of the mining operation as a system and their purpose is to maximise availability and reliability at the system bottleneck and to synchronise everywhere else.  This is at the essence of firstly being effective and then being efficient. From a maintenance perspective this means 1. Ensuring that there is a clear understanding of the operations systems bottleneck, 2. Relevant maintenance strategies are identified and are in place (particularly predictive) related to the equipment at the operational bottleneck and 3. Rules are defined which prioritise parts holdings, response times and completed plans for all failure modes at the bottleneck. Effective also means that maintenance on non-bottleneck equipment ensures that availability and reliability are synchronised so that blockage or starvation of the bottleneck is minimised. Only then should maintenance have the right to focus on efficiency
5 It is appropriate that the current bottleneck location is identified but the bottleneck identification process must be institutionalised  because a) the bottleneck can and does move, b) it is critical information for all operational activities not just maintenance and c) should be the focal point in respect to  regulating  capital and continuous improvement programmes. For example, increasing equipment performance at a non-bottleneck location is unnecessary expenditure. It is also important to consider not just where the bottleneck is now but strategically, where should the bottleneck be located and once determined, what needs to be done to move and keep it there?
6 Identifying the system bottleneck is an operational responsibility and maintenance are required to adjust its own procedures and practices accordingly. Where equipment or plant is involved, maintenance need to adopt a ‘paranoia’ type approach to both the preparation and execution of work at the system bottleneck as one minute of downtime at the system bottleneck is one minute of downtime for the whole system. i.e. the throughput is lost forever and therefore reflects itself in lost copper concentrate production
7 Variation may be due to some operations having significant mine development programmes coupled with relatively new equipment which is not due for current replacement. Typical replacement % is 2-3% of capital
8 Grade and recovery factors influence the ratio of copper produced vs. milled
10 Standard 25×365 operations
11 The number provided by Mine A appears unusually low but probably influenced by the outsourcing of some key maintenance functions
12 Stores turnover provides an annual indicator about how effective the stores spare parts holding is in meeting the needs of the maintenance function.  A relatively low number can be a suggestion that there is an existing or growing level of stores obsolescence or high percentage of insurance spares
13 This indice provides an insight into the broad matching of spares holdings with actual consumption and offers an opportunity to reduce wait time on those instances where production is unnecessarily delayed. However where this matters most is at the bottleneck and therefore reviewing the maintenance strategies and aligning the parts holdings for the bottleneck equipment would be a suggested initiative. It should also be noted that a high ratio for non-bottleneck locations is not necessarily a positive outcome as it is quite possible that there is sufficient buffer stock upstream of the bottleneck to deal with time delays, and sufficient capacity downstream
14 Distinguishing between overtime required on bottleneck vs. non bottleneck activities would provide some insight into whether the overtime is justified or not
15 Compliance to schedule is a useful indicator of whether the degree of discipline required to follow the schedule exists or not. Non-compliance can be due to many factors some of which are outside the influence of maintenance (e.g.  operations delaying equipment handover or level of planned to unplanned ratio). From a systems perspective, breakdowns on the system bottleneck should result in non-compliance to schedule but this is one of the very few reasons why schedule non-compliance is justified. If the level of breakdown is a major contributor, then again this is relevant to the extent that a) its impact on the bottleneck and b) the expenditure on unscheduled breakdowns can be as high as 3 x as much as it is when the event is planned and scheduled.
16 A relative indicator of maintenance expenditure. This indice can be influenced by a number of factors that skew the result down (e.g. low grade or low productivity giving rise to high mining costs ) or up (e.g. aging equipment). Further analysis is required to investigate root cause where the % is outside expectations
19 Provides an insight into the ratio of labour to materials in the maintenance function. Variation may be due to the contractor/employee ratio and whether overhead is included or not in the expenditure values
20 Spare parts % cost provides some insight into the level of spares and repairables used by the operation as part of the maintenance program of work. Judgements need to be made in respect to the risk of some of this expenditure being classified as operating when it is actual capital (and visa versa) thereby skewing the results for different locations
21 Indicates the ability of maintenance to ensure that the equipment is available when required to carry out its intended purpose. Note that availability is not the same as reliability (capable of performing as intended for the duration required). All these indicators suggest that the metrics are generally in-line with those included in the benchmark study. From a systems perspective, there is continued value in distinguishing between availability at the bottleneck vs. non bottleneck locations. In general availability should be maximised at the former and synchronised at the latter. This split is not evident from the statistics provided but would be a recommended split. It should also be noted that the chosen maintenance strategy can also have a significant impact of equipment availability with preventative programmes adding (sometimes unnecessarily) to the downtime by not recognising the benefits of condition monitoring in extending the mean time between repair cycles. Not all respondents provided the requested information across all indices but a general sense can still be achieved
39 It appears that the definition of what constitutes a maintainable item has influenced the degree of variation in the numbers provided.  When including equipment components (gearboxes, drive trains, chassis, etc.) the numbers will larger than for those operations who recognise a maintainable unit as one that has the ability to perform a discrete function with a operational output – e.g. a truck, a loader etc.
40 This indicator provides some insight into whether the operation has reviewed its maintenance strategies and therefore consciously aligned the strategy to the businesses requirements for that equipment. Often original equipment manufacturers propose maintenance strategies that can be self-serving  and bias a preventative approach that results in parts replacement at predefined intervals regardless of whether the equipment is showing signs of changing conditions or not (vibration, temperature, noise, etc.). The systems perspective suggests that this is particularly important for the operational bottleneck where uptime matters most. Elsewhere, the benefit of an aligned strategy translates typically in to a lower cost of maintenance where there is significant misalignment

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