Mikael
Rönnqvist
Division of Optimization
Department of Mathematics
Linköping University
As the forestry industry has become more competitive, the use of
Operations Research (OR) technologies has increased. In this seminar
I will discuss the development of two production systems for a major
forestry company in New Zealand where mathematical modeling and
optimization have a significant role. The first concerns the
despatching of logging trucks, i.e., to organise "good" trips for
trucks in a continuous process. These trucks transport logs from
harvesting locations to customers such as saw-mills and pulp-mills.
There are a large number of "constraints" which must be met. At the
same time there are many conflicting objectives which arise between
different parties, such as forestry owners, customers and truck
drivers. A difficulty is that supply of and demand for logs is
continuously changing during the day so there is a need to have
accurate information available at all times.
The second system is related to the cutting of full trees to products,
i.e. logs of different lengths and quality, at harvesting locations.
This cross-cutting is currently a manual decision process. However,
due to an increasing complexity of quality requirements and an
increasing number of products, there are also an increasing number of
logs which are out of specification. It is therefore a need to
develop systems that are capable to automate the process while at the
same time take into account quality restrictions and collect necessary
data in a production environment.