Reuse of EHRs requires data extraction and transformation processes are based on homogeneous and formalized operations in order to make them understandable, reproducible and auditable. This work aims to define a common framework of data operations for obtaining EHR-derived datasets for secondary use. Thus, 21 operations were identified from different data-driven projects of a 1,300-beds tertiary Hospital. Then, ISO 13606 standard was used to formalize them. This work is the starting point to homogenize ETL processes for the reuse of EHRs, applicable to any condition and organization. In future studies, defined data operations will be implemented and validated in projects of different purposes.