Design verification is a process that aims to get a reasonable assurance that the design developed fulfils all the applicable requirements, including those related to inputs, planning, design execution and control of interfaces.

Verification is performed using one or more methodologies, applied by a person or group different from that which carried out the design to be veri­fied. Those people will have enough access to all necessary information to perform the task.

The required verification shall be performed before the affected docu­ments are issued for purchasing, fabrication, erection or transmission to another organization in order to be used in additional design activities. When criteria cannot be reasonably fulfilled, the unverified part will be identified and controlled; in any case, the verification will be finished before the element acceptance.

The scope of the design verification depends on the safety significance of the affected element, the design complexity, the degree of normalization, the technological development status and the experience with similar previ­ous designs.

Once a design has been submitted to a design verification process, it is not necessary to repeat it for identical designs. However, the applicability of normalized or previously approved designs, against the input data and requirements, will be verified. Additionally and if it exists, the experi­ence feedback on normalized or previously approved designs shall be considered.

The original design and the verification activities shall be documented and traced in the records, allowing subsequent supervisions or audits on the applied methodology.

There are three methodologies to perform design verifications:

• Design review

• Alternative calculations

• Qualification tests.

In the following paragraphs the previous methodologies and validation will be described.