Open Pit Mine Production Scheduling using New Global Constraint

The work deals with solving one of the important problems of Scheduling Theory – the Open Pit Mine Production Scheduling Problem. To solve this problem, methods of Mixed Integer Linear Programming are widely used, the fundamental disadvantage of which is that they impose increased requirements on the amount of RAM required to store the model and implement calculations. This article presents the results that develop previous studies of the authors, in which it was proposed to solve the Open Pit Mine Production Scheduling Problem as a Constraint Satisfaction Problem, and also described the main types of global constraints for modeling the conditions of the problem under consideration. Particularly, it was proposed to represent and process the conditions for the extraction sequence of blocks using a set of global constraints max for each block separately. The study presents the Global Block Sequencing Constraint developed by the authors, which propagator (handler) analyzes the conditions for the block extraction sequence, as well as some additional requirements in one launch for all blocks in the queue of propagator, which can significantly increase the efficiency of calculations. In comparison with the methods of Integer Linear Programming, the use of the Constraint Programming Paradigm allow you to significantly decrease RAM consumption due implicit representation of constraints, which leads to the ability to solve problems with the required level of discretization of pit model.