Multi-skill resource-constrained project scheduling problem: a case study in an open-pit mining process

In this article, a case study is analysed using an adaptation of a project scheduling problem with multitasking resource restrictions. The objective is to reduce the operational costs of an open-pit mining process that uses mobile surface equipment, by allocating resources to activities, providing one or more skills, and considering constraints related to sequence, precedence, resource capacity and use, and operator allocation. To solve the problem, optimization models are proposed, i.e. single-product models with/without operator assignment, and multiproduct models with/without operator assignment. These models contribute towards the body of knowledge on optimization models for resource-constrained project scheduling problems. They were tested with real historical data from a ceramics company, considering different lot sizes and types of products, among other characteristics. The results validate the performance of the proposed models in terms of the quality of the solutions, savings and computational time for agile decision making.