What must the WPS address according to industry standards?

The Welding Procedure Specification (WPS) is a crucial document that outlines the variables and parameters necessary for welding processes to ensure that the welds made meet the specified standards and requirements. According to industry standards, the WPS must comprehensively address essential variables, non-essential variables, and supplementary essential variables.

Essential variables are parameters that significantly affect the weld quality and properties, including heat input, filler material, and joint design. Changes in these variables can lead to non-compliance with the qualification of the welding procedure. Non-essential variables, while they do not directly affect the mechanical properties of the weld, can influence other factors such as appearance or ease of the welding process. Supplementary essential variables may further refine the welding parameters or conditions under which the procedure is applied.

By covering these aspects, the WPS ensures that repeatable and reliable welds are produced in accordance with the applicable codes and standards. This thoroughness in documentation is vital for maintaining quality assurance in welding operations, which is why this particular response is considered correct.