摘要 : Availability has been widely used in industries, as a tool for measuring system performance. Reliability (R) and maintainability (M) are mainly applicable at the design stage of the system, while the supportability (S) is at the l... 展开 Availability has been widely used in industries, as a tool for measuring system performance. Reliability (R) and maintainability (M) are mainly applicable at the design stage of the system, while the supportability (S) is at the later stage, i.e., during the operating state. Unavoidable delay may directly affect the support task, which may be due to lack of spare parts, crews and improper maintenance, etc. In this work, a mathematical model to estimate the systems availability under O&M support is presented. An effect of reliability, maintainability and supportability in context to availability is also studied. The availability performance is defined to be dependent on reliability (low failure rate), maintainability (easy to repair quickly if necessary) and supportability (logistic resources in the form of spares, equipment and personnel at the right time). The first two describe system qualities; the third is the essence of the support system. The research will be helpful in understanding the effect or R, M and S parameter on the availability of mechanical systems. 收起