Reliability, maintainability and testability(RMT) are important properties of equipment, since they have important influence on operational availability and life cycle costs(LCC). Therefore, weighting and optimizing the three properties are of great significance. A new approach for optimization of RMT parameters is proposed. First of all, the model for the equipment operation process is established based on the generalized stochastic Petri nets(GSPN) theory. Then, by solving the GSPN model, the quantitative relationship between operational availability and RMT parameters is obtained. Afterwards, taking history data of similar equipment and operation process into consideration, a cost model of design,manufacture and maintenance is developed. Based on operational availability, the cost model and parameters ranges, an optimization model of RMT parameters is built. Finally, the effectiveness and practicability of this approach are validated through an example. Reliability, maintainability and testability (RMT) are important properties of equipment, since they have important impact on operational availability and life cycle costs (LCC). A new approach for optimization of RMT parameters are proposed. First of all, the model for the equipment operation process is established based on the generalized stochastic Petri nets (GSPN) theory. Then, by solving the GSPN model, the quantitative relationship between operational availability and RMT parameters is obtained. Afterwards , taking history data of similar equipment and operation process into consideration, a cost model of design, manufacture and maintenance is developed. Based on operational availability, the cost model and parameters ranges, an optimization model of RMT parameters is built. and practicability of this approach are validated through an example