Commentary to CSA Standard CAN/CSA-S471-92, General Requirements, Design Criteria, the Environment and Loads
1.2 Alternative Design Procedures
The intent of Clause 1.2.1 is to allow flexibility in the use of design methods that are not totally in accordance with the requirements of the Standard but that can be justified by proven performance or by theory and analysis based on special investigations. Such investigations might include
(a) evaluation of a full-scale structural element or a prototype structure by a loading test, supplemented by calculations as required;
(b) studies of a scale model or a combination of model tests and calculations; or
(c) observed behaviour of existing structures similar to the one being designed.
The key point in the Clause is that the levels of safety and p erformance required by the Standard must be achieved by whatever design process is used.