The proposed work deals with the evaluation and improvement of a Z-source inverter using simulation. A Z-source inverter is a type of power inverter, a circuit that converts direct current to alternating current. It functions as a buck-boost inverter without making use of a DC-DC converter-bridge due to its unique circuit topology. MIL-HDBK-217F (Military handbook) is used to evaluate the reliability of this Z-source inverter. We have proposed a system that has been theoretically proved to have the lowest failure rate leading to reduced system repairing because of the use of redundant switches. The MTBF (mean time between failure) is high for redundant switches which will increase the life of the inverter. Simulation of the proposed system is done on MATLAB and a comparison of the reliability of the Z-source inverter is done with the results found theoretically. In a conventional inverter if one switch of inverter fails the complete leg will fail. Whereas in our case that is in Z-source inverter, because of the intermediate shoot through stage redundant switch will replace the failed switch thus saving it from failure.