Maintenance processes for container handling equipment using P-time petri nets

To ensure the safety in seaport terminal,many maintenance activities should be done every year. however,frequent and delayed maintenance activities would cause low service quality and require large sums of money. therefore,a study of maintenance scheduling in seaport is needed to be carried out. the aim of this paper is the study and the design of a maintenance module based on petri nets (pns) for container handling equipment. in this context,we propose a new p-time petri net for maintenance (ptpnm). this tool includes spare parts,maintenance group and deterioration process. the ptpnm can give a true expression of the system operation process by introducing time,which is suitable for process indexes calculation and evaluation such as equipment maintenance,support resources utilization,mission success rate and average waiting time.