STOCHASTIC ANALYSIS OF PRINTED CIRCUIT BOARDS MANUFACTURING SYSTEM CONSIDERING REPAIRS BY INTERNAL/EXTERNAL ENGINEERS AND ARBITRARY ARRIVAL TIME OF EXTERNAL ENGINEERS

In the present paper, a stochastic model for the system involved in the printed circuit boards(PCBs) manufacturing process is developed. The manufacturing process, based on Surface Mount Technology (SMT), is carried out in three stages viz. printing, placing and soldering through a hardware-software system. During the process, inspections, maintenances and repairs on occurrence of faults of the system are done by internal/external engineers. The internal engineers inspect the system and every manufactured PCB. The system's software faults as well as faults in the PCBs are repaired by the internal engineers whereas system's hardware faults are repaired only by the external engineers. In the model, possibilities of different kinds of faults, online PCB's repairs and arbitrary arrival time of the external en- gineers, are also incorporated. The expressions for various measures of system performance have been derived using Markov process and regenerative techniques. In the last, numerical computation and graphical analysis have been given for a particular case to show the effect of various parameters on the system performance and cost-benefit.