Gas-fired power generator (GPG) planning in the integrated gas-electricity systems (IGES) is the fundamental guarantee for optimal utilization of natural gas energy. The reliability level is significant for GPG planning to ensure the secure operation of IGES. However

existing planning research considering reliability focuses on the system-level reliability index

which rarely accurately reflects GPG reliability's importance. A set of device-level reliability indices is proposed to consider the characteristics of GPG in IGES

which enriches the reliability index set and provides a complete index system for planning and considering reliability. Furthermore

solving the GPG capacity and location planning model considering the reliability index is time-consuming and difficult to solve directly. For enhancing the solving efficiency

a point-to-point mathematical mapping relationship of the reliability index and the GPG planning is constructed based on bilinear interpolation theory. Based on the proposed mapping relationship and reliability index

a novel GPG fast planning method is established to obtain the optimal planning scheme of GPG meeting reliability requirements directly. This method avoids repeatedly adjusting the optimization scheme to meet the reliability index. Finally

a modified IEEE 24-bus power system combined with an NGS 10-node gas system is adopted to verify the effectiveness of the established model and proposed method.