This Technical Specification provides a workflow for the execution, validation, verification and documentation of a numerical welding simulation within the field of computational welding mechanics (CWM). As such, it primarily addresses thermal and mechanical finite element analysis (FEA) of the fusion welding (see ISO/TR 25901:2007, 2.165) of metal parts and fabrications.CWM is a broad and growing area of engineering analysis.This Technical Specification covers the following aspects and results of CWM, excluding simulation of the process itself:— heat flow during the analysis of one or more passes;— thermal expansion as a result of the heat flow;— thermal stresses;— development of inelastic strains;— effect of temperature on material properties;— predictions of residual stress distributions;— predictions of welding distortion.This Technical Specification refers to the following physical effects, but these are not covered in depth:— physics of the heat source (e.g. laser or welding arc);— physics of the melt pool (and key hole for power beam welds);— creation and retention of non-equilibrium solid phases;— solution and precipitation of second phase particles;— effect of microstructure on material properties.The guidance given by this Technical Specification has not been prepared for use in a specific industry. CWM can be beneficial in design and assessment of a wide range of components. It is anticipated that it will enable industrial bodies or companies to define required levels of CWM for specific applications.This Technical Specification is independent of the software and implementation, and therefore is not restricted to FEA, or to any particular industry.