This report describes how to organise inter-comparison tests and how to statistically analyse the test results. In this report, relevant definitions, instructions, requirements and criteria from ISO, ASTM, EN standards, as well as national specifications are summarised and some examples of inter-comparison tests from practical applications are presented. The definitions of various terms commonly used in inter-comparison tests are given in Chapter 2. The complete procedures for organising inter-comparison tests are described in Chapter 3, while some useful statistical tools for analysing test results are given in Chapters 4 and 5. Practical applications of the precision test results are presented in Chapter 6 and, finally, the concluding remarks are given in Chapter 7.