ISO 17534-1 describes quality requirements and measures to ensure, to indicate, and to verify the degree of conformity of a software program with a consistently implementable calculation method/procedure.The main objective of ISO 17534-1 is to ensure that applying a consistent implementable calculation method with different quality assured software products on an identical set of input data will produce the same results within a defined range of acceptable deviations.ISO 17534-1 enables the producer of this type of software to declare and to proof the correct implementation of a calculation method and the software user to verify it without the necessity of a third-party certification. It takes into account that software developers and software users are members of the same scientific-technical community and offers means and measures for a transparent and open communication between them.ISO 17534-1 does not cover the aspect of correctness of the calculation method itself, i.e. especially the agreement of calculated results with results obtained with measurements will not be touched.