Steam turbine availability is of crucial importance, especially in ethylene refineries. Based on positive experiences with Siemens, the customer decided to pursue a revamp because they trust the Siemens OEM solution. The customer, one of the largest ethylene plants in Asia, was built in the 21st century and aimed for a power upgrade in order to operate the driven compressor with a higher gas mass flow. Since the higher speed /power output can cover the degradation of the compressor, the customer was also interested in an availability increase for their SST-600 steam turbine.