Problems of Outsourcing when Repairing and Servicing Production Equipment

The article is devoted to the issue of calculation of stationary probabilities of states of the system of mass servicing with unreliable equipment, servicing and re-adjustment at the beginning of the production cycle. The article describes functioning both of the main and auxiliary material flow of the logistic system. It is supposed that the incoming flow for processing or orders has a Poisson distribution and the time of breakage of equipment, the time of re-adjustment and the time of servicing have indicative laws of distribution. Equipment is serviced by two crews: maintenance and service. The maintenance crew repairs broken equipment and the orders on the device are not lost but are serviced during the time left. The second crew deals only with servicing works. The article considers one of the possible schemes when the equipment required for completion of the production cycle is sent for servicing. There are no restrictions with respect to the length of the queue. The article finds main characteristics of the above described system, namely: probability that the device is not in working condition and is sent for servicing and re-adjustment. The found probabilities of states of the described system could be used for assessment of expediency of the repair outsourcing at industrial enterprises.