FOR THE PETROLEUM INDUSTRY, STANDARD TEST METHODS, SPECIFICATIONS, and practices developed under the jurisdiction of ASTM D2 Committee on Petroleum and Petroleum Products or ISO TC28 Technical Committee on Petroleum Products are globally accepted. A conscious decision has been made to maintain technical harmony between standards produced by both organizations on similar subject matters. The purpose of this chapter is to familiarize readers with statistics-based metrics for test method performance that have been adopted by both organizations and the relevant standard practices to quantify, monitor, maintain, and use these metrics.