Validation of software in measuring instruments

Most measuring instruments of today are based on embedded systems or personal computers. The software embedded into the instruments controls functions that must be possible to verify and validate. Validation of software is certainly performed by the developing companies, but also the independent test laboratories must be able to perform the validation. Traditional evaluation of measuring accuracy and resistance to environmental stress is not enough to confirm the functionality of the instrument. An efficient validation procedure often combines different kinds of validation methods. The set of validation methods can be collected as a “tool box” which can be applied differently for different measuring instruments. The risk classes, the validation guidance and some possible validation methods are discussed. The paper is based on the work carried out by the European project “MID-Software”.