# Verification

ASTM E1355 *Standard Guide for Evaluating the Predictive Capability of
Deterministic Fire Models* (2018) defines *model validation* as “the
process of determining the degree to which a calculation method is an
accurate representation of the real-world from the perspective of the
intended uses of the calculation method.”

ASTM E1355 *Standard Guide for Evaluating the Predictive Capability of
Deterministic Fire Models* (2018) defines *model verification* as “the
process of determining that the implementation of a calculation method
accurately represents the developer’s conceptual description of the
calculation method and solution to the calculation method.” Slightly
different definitions of *model verification* are used by other
standards in other industries, but in general verification involves
assessing whether the underlying mathematical formulation is correctly
implemented in the source code - or “is the math right”.

Model verification is typically approached by simulating simple canonical problems and comparing model outputs to exact solutions, where available. ELMFIRE has been subjected to extensive model verification exercises since development began in 2010. In an effort to promote transparency and authenticity, ELMFIRE’s mathematical formulation is documented in the Technical Reference, its source code is maintained in a public Git repository, and several model verification test cases are presented below (with associated scripts and inputs available in the Git repo).