Software validation in metrology: A case study for a GUM-supporting software

Software validation in metrology is a crucial, often highly interdisciplinary process. One needs to consider all steps beginning with the definition of requirements and ending with the provision of evidence that the requirements are fulfilled. This includes the refinement of requirements to testable attributes, the selection of appropriate validation methods, the proper execution of methods and the documentation of results. As regards the validation methods, functional tests of measuring devices are preferred in metrology, although this is not always justified. Dynamic tests of the executable software code as well as code inspections may be very beneficial and often more straightforward than expected.An extended approach of validation in metrology that includes a rigorous refinement of requirements, dynamic software tests and code inspections is demonstrated by a case study. The target of validation is a software that claims to be conform to the Guide to the Expression of Uncertainty in Measurement (GUM). The contributions of various validation methods to confirm the fulfilment of requirements related to GUM and the benefits of this approach are shown.