The success of modern manufacturing methodologies, such as Lean Manufacturing or TPM (Total Productive Maintenance), heavily relies on accurate measurement and analysis of production data. The concept of OEE is born as a KPI (Key Performance Indicator) associated with the standard TPM production improvement program. The advantage of the OEE among other reasons is that it measures, in a single indicator, by a percentage, all the fundamental parameters in industrial production: availability, perfarmance, and quality. Since its creation, in the '80s, its main criticism has been that the three components are equally important. Different proposals have been designed about how to modifr weights, some of them based on costs, although in these cases the resulting indicator is expressed in monetary units instead of a percentage. This paper presents a methodology that adjusts the final value qf each of the components of the OEE based on costs (OEEAxC), expressing the indicator as percentage, and is applied in a metal-mechanical company to a steel cutting machine.