Towards optimum value in underground mine scheduling

2009

Lorrie Fava, Paul Dunn, John Fitzgerald, Shawn Wilson,

The scheduling of mining activities is a complex task; in particular because of the requirement to satisfy a large number of constraints. Optimizing the value of a mine schedule is a daunting endeavour with the potential to increase the value of a project. A Schedule Optimization Tool (SOT) for underground mine planning is described, and its use for investigating strategic decisions is illustrated by means of a case study. The main components of SOT include: a genetic algorithm, which searches for optimal schedules; guidance, the application of heuristic rules to guide the genetic algorithm; and sliding, which implements just-in-time development. SOT is employed to compare schedules at various ore capacities, accounting for the appropriate financials in each schedule evaluation. The case study finds that preliminary scheduling performed before invoking SOT, providing a good starting point for the search, does not ultimately lead to higher value schedules. Two key uses for SOT are identified. A mine planner can save time by using SOT to produce high-value scheduling alternatives. This process ensures a broader investigation of the value that the deposit can yield. Also, SOT can be used to validate strategic and tactical decisions that have been made through manual scheduling practices. Both uses produce high value schedules conforming to all resource constraints.

Keywords: Scheduling, Optimization, Planning, Underground mining, Evaluation, software tool, Automation, Decision Support, strategic options, Valuation