This International Standard covers the methodology for the application of precision estimates of a test method derived from ISO 4259-1. In particular, it contains the procedures for setting the property specification limits based upon test method precision where the property is determined using a specific test method, and in determining the specification conformance status when there are conflicting results between supplier and receiver. Other applications of this test method precision are briefly described in principle without the associated procedures which are planned to be covered in a future Part of this Standard. The procedures in this International Standard have been designed specifically for petroleum and petroleumrelated products, which are normally homogeneous. However, the procedures described in this International Standard can also be applied to other types of homogeneous products. Careful investigations are necessary before applying this International Standard to products for which the assumption of homogeneity can be questioned.