A Finite-Domain Constraint-Based Approach on the Stockyard Planning Problem

Transport problems are a significant challenge for companies, i.e. due to concerns about climate change and the constant increase in raw material prices, such as for petrol. One issue in transporting bulk materials is the Stockyard Planning Problem (SPP), which plays a crucial role in mine production scheduling and bulk material transportation by using stockpiles to store and blend raw material. The SPP aims to: 1) blend superior and inferior components to achieve a desired quality, 2) transfer material from import (e.g. ocean-going ships) to interim storage (e.g. stockpiles) and then to export (e.g. docks at inland ports), and 3) find a time-/cost-optimized schedule for working steps of 1 and 2. This paper presents a novel constraint-based approach for solving the Stockyard Planning Problem (SPP) by utilizing new abstractions such as time, storage, and potential movements within a stockyard system.