Abstract:
In northeast China, logging has three stages; timber
harvest, transportation and the operations inside a timber
yard. The timber yard is an intermediate transhipment point
between truck transport and rail transport to manufacturing
centers. The transhipment capacity of the timber yard is
often the limiting acitivity in the logging chain.
Since the transportation is the middle part, its
management affects both the technology and the economics of
the other two. At the same time, the other two stages
provide constraints to the transportation operations.
The objective of this paper is to find an optimal
economic plan for assigning trucks to timber yards in such a
way as to minimize the number of trucks while satisfying the
delivery schedule for the timber yard. This is done by
controlling the log truck arrival distribution over time. As
a result, the fewest number of trucks are used and the
timber yard is efficiently used.
A computer program was developed to provide the
transportation manager with detailed information about truck
allocations and to permit rapid updating of the
transportation plan.
The truck allocation problem is formulated as a
capacitated network problem and the out-of-kilter algorithm
is used to solve it. After the network problem is solved,
the number of trucks needed to carry out the schedule can be
determined through an hour-by-hour truck inventory analysis.
