Rule of Six: a subsystem-based approach to compliance assurance of system solutions

System integrators face the challenge of verifying legal EMC compliance of an ever larger number and variety of modular components prior to offering integrated solutions for sale to end users. In some cases, it is practically impossible to physically test the maximum number and combination of these options. This paper suggests a building block method to: (1) test a limited number of like modular components to represent larger numbers of the component used in an integration (Rule of Six test method); (2) avoid combination testing of dissimilar modular components if each of the components his been tested and qualified per the Rule of Six test method. In addition, this paper compares the Rule of Six methodology with the CISPR work on alternate rules for applying the statistical 80/80 rule. This comparison concludes that individual statistical testing of multiple production samples (as suggested by the CISPR 22 audit sampling test) should not be necessary if the Rule of Six test method is performed. This paper also discusses how Sun Microsystems Incorporated has successfully applied Rule of Six testing for various product integrations.