ISO 20332:2016 sets forth general conditions, requirements, methods, and parameter values for performing proof-of-competence determinations of the steel structures of cranes based upon the limit state method. It is intended to be used together with the loads and load combinations of the applicable parts of ISO 8686.

ISO 20332:2016 is general and covers cranes of all types. Other International Standards can give specific proof-of-competence requirements for particular crane types.

Proof-of-competence determinations, by theoretical calculations and/or testing, are intended to prevent hazards related to the performance of the structure by establishing the limits of strength, e.g. yield, ultimate, fatigue, and brittle fracture.

According to ISO 8686‑1 there are two general approaches to proof-of-competence calculations: the limit state method, employing partial safety factors, and the allowable stress method, employing a global safety factor. Though it does not preclude the validity of allowable stress methodology, ISO 20332 deals only with the limit state method.

Proof-of-competence calculations for components of accessories (e.g. handrails, stairs, walkways, cabins) are not covered by this International Standard. However, the influence of such attachments on the main structure needs to be considered.