ISO 16733-1:2015 describes a methodology for the selection of design fire scenarios that are credible but conservative for use in fire safety engineering analyses of any built environment, including buildings, structures or transportation systems. Following the procedures given in this part of ISO 16733-1:2015, a manageable number of design fire scenarios is selected using a qualitative or semi-quantitative approach. For a full quantitative approach using risk assessment, the reader is directed to ISO 16732‑1.