ISO 4259-2:2017 specifies the methodology for the application of precision estimates of a test method derived from ISO 4259‑1. In particular, it defines 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.
The procedures in ISO 4259-2:2017 have been designed specifically for petroleum and petroleum-related products, which are normally homogeneous. However, the procedures described in ISO 4259-2:2017 can also be applied to other types of homogeneous products. Careful investigations are necessary before applying ISO 4259-2:2017 to products for which the assumption of homogeneity can be questioned.