This document specifies principles and requirements for the determination of greenhouse gas (GHG) emissions from sector-specific sources such as from steel and iron, cement, aluminium, lime and ferroalloy-producing industries. This document specifies definitions and requirements valid to the sector-specific parts of ISO 19694 series. It provides common methodological issues and defines the details for applying the requirements for the harmonized methods, which include: measuring, testing and quantifying methods for GHG emissions of the above-mentioned sector-specific sources in the cited standards; assessing the level of GHG emissions performance of production processes over time at production sites; establishing and providing reliable, accurate and quality information for reporting and verification purposes. The application of this document to the other sector-specific standards in the ISO 19694 series ensures accuracy, precision and reproducibility of the obtained results. For this reason, it is a generic standard.