In this study, thermodynamic analysis is implemented to the kerosene‐fuelled high by‐pass turbofan (HBP‐TF) engine to assess entropy, exergy, environmental, and sustainability metrics for different design variables such as pressure ratio of high‐pressure compressor (HPC‐PR) ranging from 7.5 to 8.5 and turbine inlet temperature (TIT) varying from 1400 to 1525 K considering variable needs in the aviation industry. As a novelty, entropic improvement potential (EIP) index for turbomachinery components and specific irreversibility production for the whole engine are calculated. Sustainability‐based parameters for different cases are compared with the baseline values of the HBP‐TF engine. The combustor has the highest entropy production of 44.4425 kW K−1 at the baseline. The higher TIT increases the entropy production of the combustor by 16.56%, whereas the higher HPC‐PR decreases it by 5.83%. The higher TIT and HPC‐PR favorably affect the sustainable efficiency factor of the engine, which is observed as 1.5482 at baseline and increases by 4.5% and 0.058% with the increment of TIT and HPC‐PR, respectively. The higher TIT and higher HPC‐PR results in lowering sustainability of the engine. The specific irreversibility production of the engine decreases by 3.78% and 0.1171% respectively, as TIT and HPC‐PR reach the highest point considered in the study.