Development of a Hierarchical Timed Coloured Petri Net Model for Automobile Maintenance Service Centre

The increasing complexity of modern automobiles, coupled with the growing demand for efficient maintenance services, has intensified the need for robust process modelling techniques capable of improving service delivery in automobile maintenance service centres. Many service centres continue to experience operational challenges such as prolonged vehicle waiting times, excessive queue lengths, delayed service completion, and low resource utilization, leading to reduced customer satisfaction. Existing modelling approaches have primarily focused on isolated maintenance activities, particularly engine servicing, and are inadequate for representing integrated maintenance systems involving both engine service and running repair operations. This study presents the development of a Hierarchical Timed Coloured Petri Net (HTCPN) model for automobile maintenance service centres that captures the concurrent, stochastic, and hierarchical characteristics of maintenance processes. Operational data were collected from DDD Motors Service Centre, including vehicle arrival times, service commencement and completion times, and routing information for engine service and running repair activities. The collected data were analysed using the ARENA Input Analyzer to determine the probability distributions used as model input parameters. The proposed HTCPN model was developed using a hierarchical structure comprising a top-level module representing the overall maintenance workflow and four interconnected sub-modules: Arrival–Reception, Engine Service, Running Repair, and Quality Assurance–Car Wash. The model incorporates timed transitions, coloured tokens, guard functions, and hierarchical substitution transitions to accurately represent service processes, resource allocation, and vehicle movement through the maintenance system. Structural verification confirmed that the model is logically consistent, modular, scalable, and capable of representing concurrent maintenance operations without deadlocks. The developed HTCPN model provides a comprehensive framework for modelling integrated automobile maintenance service processes and establishes a reliable foundation for subsequent simulation, performance evaluation, and operational optimization. The proposed modelling approach offers an effective decision-support tool for improving service efficiency, reducing operational bottlenecks, and enhancing maintenance service delivery in automobile service centres and similar discrete-event systems.

Keywords: Hierarchical Timed Coloured Petri Net, Automobile Maintenance Service Centre, Modelling, Discrete Event Systems, Service Operations.