||This paper reports the findings of the study of maintenance policies for the IBM 1620 system installed at the university's computing center. Three Maintenance policies were investigated by studying the operating characteristics of the system's two functional units, IBM 1620 Processor and IBM 1622 Card-Punch, covering the period of twenty-nine months. Cost minimization approach is used to determine the optimum policy among three alternatives. These three alternatives are: 1) repairs only; 2) scheduled maintenance at a time interval of t hours of operation without failure; 3) performing maintenance procedures at t, 2t, 3t, ⋯ regardless of intervening repairs. The problems of gathering information and the condition of optimum for the alternatives 2 and 3 are discussed. The empirical result of this study is in favor of alternative 1 for servicing both functional units, 1622 and 1620.