Application of a max-min-plus discrete event model to the operation of a heavy-haul iron-ore railway

The heavy-haul iron-ore railways in Western Australia now transport more than 300 Mt of ore per year which is worth more than US$15 billion. Strong demand is seeing many new smaller mines and transport operations enter the industry. Optimization of the mining, rail and port infrastructure has become a substantial issue due to high investment costs but also very high returns. There are several types of model that can be used to represent the system at different levels of abstraction, and provide a framework for pursuing various optimization approaches. This paper employs a discrete event type of model based on the max-min-plus algebra and an optimization approach based on timed event graph throughput. In doing so it provides a useful basis for the exploration of performance improvement in key `bottlenecks' in the iron-ore `production' process: the railway mainline and the unloading process in the ore-car dumpers.