Underground mine scheduling decision-making has been based on production requirements, equipment productivities and the mine planner’s instincts on the best scheduling strategy for the mine to optimise the net present value (NPV) of a project.
In the last few years, innovative software has been developed to optimise underground schedules based on NPV. The schedule optimisation tool (SOT) allows the user to set up scenarios based on grade, metal content, capital and operating costs.
This paper discusses the results of two case studies undertaken using the SOT software to optimise the NPV of the projects.
In each case study, the SOT software has been applied in two ways:
1. Using the original mine planner’s scenario and determining whether the NPV could be improved by changing resource capacities
2. Changing the scheduling goals to determine whether a different mining strategy would have a better NPV outcome.
The outcomes of the case studies demonstrate that the mine layout and design were contributing factors to the overall improvement of the NPV and that SOT has a more noticeable impact on the NPV of projects where less sequence constraints are required, such as geotechnical sequencing and access development.
