Operations performed by a maintenance service provider (MSP) can include the entire maintenance function or select activities; these need to be well-balanced in terms of utilisation rate of own resources, maintenance cost incurred and the uptime of the customers’ production systems. MSPs face challenges due to the task of planning several non-associated plants and with a frequent lack of reliable information. In this research work, an agent-based decision support system of service-related maintenance has been developed. Research shows that this approach can improve the understanding of the problem domain and also generate a basis for decision-making and structural changes.