ISO 9000 registration (or EN 29000 certification) is used widely in Europe on a voluntary basis as a condition of acceptance of a manufacturer's product or as a way of recognizing the manufacturer's credibility. While a quality system such as ISO 9000 indicates that a company has an efficient organization structure and has low failure costs, it does not always certify conformity with the CE marking directives. However, some directives require use of a quality management system as part of the conformity assessment.
For example, the Machine Directive requires manufacturers to set up a quality control system to make sure that future products coming off an assembly line meet CE marking requirements. However, the quality control system does not have to be ISO 9000, although ISO 9000 is a good choice, since it is widely recognized. The Medical Device Directive does require ISO 9000 (EN 13485) as part of the conformity assessment process.