Andres Weintraub

A Review of Operations Research in Mine Planning

Applications of operations research to mine planning date back to the 1960s. Since that time, optimization and simulation, in particular, have been applied to both surface and underground mine planning problems, including mine design, long-and short-term production scheduling, equipment selection, and dispatching, inter alia. In this paper, we review several decades of such literature with a particular emphasis on more recent work, suggestions for emerging areas, and highlights of successful industry applications.

Forest management challenges for operational researchers

This is an overview of operational research work that has been carried out to support strategic forest management planning, short term forest planning, forest operations, and forest fire management. It identifies important unresolved problems and new challenges that could serve as a rich source of problems for both practitioners and researchers.

Using Operational Research for Supply Chain Planning in the Forest Products Industry

Abstract Over the years, Operational Research (OR) has been used extensively to support the forest products industry and public forestry organizations (e.g., governments, environmental protection groups) in their respective planning activities concerning the flow of wood fiber from the forest to the customer. The applications deal with a wide range of problems, ranging from long-term strategic problems related to forest management or company development to very short-term operational problems, such as planning for real-time log/chip transportation or cutting. This paper presents an overview of the different planning problems and reviews the past contributions in the field of forestry, with a focus on applications and problem descriptions. In the context of the 50th anniversary of the Canadian Operational Research Society, this paper also recognizes the contributions of many Canadian researchers to the field of forestry management.

Operations Research Models and the Management of Agricultural and Forestry Resources: A Review and Comparison

Operations research (OR) has helped people to understand and manage agricultural and forestry resources during the last 40 years. We analyzed its use to assess the past performance of OR models in this field and to highlight current problems and future directions of research and applications. Thus, in the agriculture part, we concentrate on planning problems at the farm and regional-sector level, environmental implications, risk and uncertainty issues, multiple criteria, and the formulation of livestock rations and feeding stuffs. In the forestry part, we concentrate on planning problems at the strategic, tactical, and operational levels, implementation issues, environmental implications, as well as the treatment of uncertainty and multiple objectives. Finally we made a comparison between the two areas in terms of problem types, problem-solving approaches, and reported applications.

Harvest Scheduling Subject to Maximum Area Restrictions: Exploring Exact Approaches

We consider a spatial problem arising in forest harvesting. For regulatory reasons, blocks harvested should not exceed a certain total area, typically 49 hectares. Traditionally, this problem, called the adjacency problem, has been approached by forming a priori blocks from basic cells of 5 to 25 hectares and solving the resulting mixed-integer program. Superior solutions can be obtained by including the construction of blocks in the decision process. The resulting problem is far more complex combinatorially. We present an exact algorithmic approach that has yielded good results in computational tests. This solution approach is based on determining a strong formulation of the linear programming problem through a clique representation of a projected problem.

Use of Or Systems in the Chilean Forest Industries

The Chilean forestry sector is composed of private firms that combine large timber-land holdings of mostly pine plantations and so me eucalyptus with sawmills and pulp plants. Since1988, to compete in the world market, the main Chilean forest firms, which have sales of about

School redistricting: embedding GIS tools with integer programming

1 billion, have started implementing OR models developed jointly with academics from the University of Chile. These systems support decisions ondaily truck scheduling, short-term harvesting, location of harvesting machinery and access roads, and medium- and long-term forest planning. Approaches used in solving these complex problems include simulation, linear programming withcolumn generation, mixed-integer LP formulations, and heuristic methods. The systems have led to a change in organizational decision making and to estimated gains of at least US

Operational research models and the management of fisheries and aquaculture: A review

20 million per year.

A Problem of Forest Harvesting and Road Building Solved Through Model Strengthening and Lagrangean Relaxation

The paper deals with a school redistricting problem in which blocks of a city must be assigned to schools according to diverse criteria. Previous approaches are reviewed and some desired properties of a good school districting plan are established. An optimization model together with a geographic information system environment are then proposed for finding a solution that satisfies these properties. A prototype of the system is described, some implementation issues are discussed, and two real-life examples from the city of Philadelphia are studied, one corresponding to a relatively easy to solve problem, and the other to a much harder one. The trade-offs in the solutions are analysed and feasibility questions are discussed. The results of the study strongly suggest that ill-defined spatial problems, such as school redistricting, can be addressed effectively by an interaction between objective analysis and subjective judgement.

A combined transportation and scheduling problem

Abstract This paper reviews the role that the operational research (OR) discipline has played in the understanding and management of renewable resources in the areas of fisheries and aquaculture. The analysis is undertaken with two purposes. First, to assess the past performance of the OR models in this field. Second, to highlight current problems and future directions of research.