The study presents selected issues related to a broadly defined technical maintenance of production process continuity in the scope of productive maintenance systems and their reliability in a large clothing enterprise. In a given period of time every real technical system undergoes various changes which may result from spontaneous processes or external influences directly affecting its reliability. The first part of the article contains the analysis of reasons for absence of production process continuity based on literature research and individual observations. The second part presents random individual research related to reliability of a selected Pfaff 3588 automatic sewing unit. The conclusion contains the suggested preventive and corrective actions aimed at improvement of a functioning productive maintenance system.