This part of ISO/TR 13387 provides guidance on procedures for assessing and verifying the accuracy and applicability of deterministic mathematical fire models used as tools for fire safety engineering. It does not address specific fire models. It is not a step-by-step procedure, but does describe techniques for detecting errors and finding limitations in a calculation model. This part of ISO/TR 13387 does not address the assessment and verification of totally probabilistic approaches to fire safety calculations, or the probabilistic elements that may be combined with deterministic calculations.