adoption of either a volume strategy or a
cost strategy.
Neither one nor the other
During periods of high commodity prices,
such as occurred over the past decade,
mining companies tend to adopt a
volume strategy. An effective uptake of
the volume strategy during the
2003 – 2011 boomwould logically have
seen loader performance increase and
truck performance decline during this
time. This was not the case, however.
Instead, both truck and loader
performance increased and
then decreased over the decade (Figure 1).
Although loader performance did
improve through to 2009, the falls in 2010
and 2011 were not expected from an
industry attempting to maximise output.
The fact that both loader and truck
performance increased from 2003 – 2006 is
likely more a function of the take-up of
underutilised capacity that resulted from
the previous period of lower commodity
prices, rather than a demonstration of an
effective volume strategy.
The efficient execution of a cost
strategy after the 2003 – 2011 boomwould
have seen individual truck performance
increase (as numbers were optimised to
minimise unit cost) and loader
performance level off or even decline. The
fact that both loader performance and
truck output declined during this time,
however, creates doubt that it was a
strategy-related result.
Another way that equipment‑level
data can be used to assess the
effectiveness of a mining strategy is
through the effective over-trucking (EOT)
metric. EOT is the percentage of available
time trucks are waiting or the loader is
loading. Looked at another way, it is the
time the loader is not waiting on trucks.
An increase in EOT supports maximising
volume output, while a reduction in EOT
is suggestive of mines becoming more
focused on unit cost.
To a large extent the trends in EOT
over the past decade (Figure 2) reflect the
macro-economics of the industry. From
2003 – 2009, mines increased EOT by
approximately 8% to increase loader (and
subsequently total mine) output. Between
2012 – 2013, they reduced EOT to reduce
costs. In between these periods, the
financial crisis caused a short-term
pullback in EOT, again to reduce costs.
Acombined interpretation of Figure 1
and Figure 2 suggests the industry’s
strategic approach to mining over the past
decade was not optimised, for the
following reasons:
n
n
Truck output rose from 2003 – 2006:
the effective execution of a volume
strategy during a boomwould
typically see more trucks used with
individual truck output falling.
n
n
Loader output declined from
2009 – 2011: the effective execution
of a volume strategy during a boom
would typically see more trucks used
with loader output increasing.
n
n
Truck output declined from
2011 – 2013: the effective execution of
a cost strategy during a bust would
typically see fewer trucks used with
individual truck output increasing.
n
n
All EOT results are between 43%
and 53% over-trucking. Optimum
performance would be 100% or 0%:
a result near 50% suggests a lack of
understanding of an appropriate
strategic approach by a significant
portion of the industry.
The performance that goes into these
results is more complex than these
plots indicate.
The key constraints to
truck-and-loader operations
The core constraint of a truck-and-loader
operation is that the fleet is structured,
measured andmanaged in parts, rather
than as a whole. The results of this
include: lower than expected overall
performance results; difficulties
Figure 1.
Opencast loader and truck performance, 2003
–
2013 (2003 = 100%).
Source: PwC’s Equipment Productivity and Reliability Database.
Figure 2.
Effective overtrucking, 2003
–
2013.
Source: PwC’s Equipment Productivity and Reliability Database.
80%
85%
90%
95%
100%
105%
110%
115%
120%
Loaders Trucks
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
40%
42%
44%
46%
48%
50%
52%
54%
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
26
|
World Coal
|
September 2014
