  We investigate a fundamental model from open-pit mining, which is a cyclic
system consisting of a shovel, traveling loaded, unloading facility, and
traveling back empty. The interaction of these subsystem determines the
capacity of the shovel, which is the fundamental quantity of interest. To
determine this capacity one needs the stationary probability that the shovel is
idle. Because an exact analysis of the performance of the system is out of
reach, besides of simulations there are various approximation algorithms
proposed in the literature which stem from computer science and can be
characterized as general purpose algorithms. We propose for solving the special
problem under mining conditions an extremely simple algorithm. Comparison with
several general purpose algorithms shows that for realistic situations the
special algorithm outperforms the precision of the general purpose algorithms.
This holds even if these general purpose candidates incorporate more details of
the underlying models than our simple algorithm, which works on a strongly
reduced model. The comparison and assessment is done with extensive simulations
on a level of detail which the general purpose algorithms are able to cover.
