Development of route oriented Petri net for cycle time evaluations in SMT assemblies industries

The surface mounting technology (SMT) assembly procedures consist of calibrating the printed circuit board (PCB); vacuuming components form the feeder stations; compensating the orientation of the vacuumed surface mountable component (SMC); placing SMC chips on PCB. To increase the throughput of the assemblies, the synchronous vacuuming of SMC components is designed. Evaluating the cycle times of SMT assemblies requires the modeling of the specified times of image processing, vacuuming and releasing components and the route dependent robot movement times. In this paper, the route oriented Petri nets (ROPN) is newly proposed to solve the SMT assembly problems in flexible routes. Based on the ROPN modeling capabilities, the flexible component mounting routes and the synchronous vacuuming procedures can be modeled actually. Finally, two actual testing PCB board data were evaluated and the results had been compared with the actual cycle times to verify the proposed approaches.