Software testing and preventive quality assurance for metrology

Software controlled measuring systems can be approved with the help of different kinds of conformity assessment techniques based either on the final product, the product design or corresponding development and production processes. To validate the software as an integral part of the measuring system, different approaches of software quality assurance have to be applied for different conformity assessment procedures. There are two essential categories of software quality assurance, both of which supplement each other. On the one hand side, analytical methods of software testing, static analysis, and code inspection are used in the scope of conformity assessments of final or intermediate products. On the other hand, preventive audits of software development processes are applied to evaluate and improve appropriate software processes and to consequently support process related conformity assessment procedures. Depending on the validation objectives, validation methods, audit areas, and the appropriate requirements have to be selected and refined. A major problem of validation efforts, namely the process of defining and refining testable requirements, can be solved with the help of international software standards. In Germany, the accredited software testing laboratory at PTB supports software quality in metrology.