For many organizations, certification/registration is a requirement to be a supplier to many organizations.
Certification is a means to ensure your organization and your customer that you have effectively implemented a management system. Further, that the system truly provides the means to ensure that your products or services are developed with consistency, quality, and customer expectations in mind.
Organizations implement and register a Quality Management System (QMS) because they are aware of the benefits associated with both the management system and certification. With the added audits performed by the certification body, your organization has access to valuable information like industry trends and best practices; a second set of eyes that can identify areas of needed improvement in the system where your internal audit team may not; and finally, recognition in the efforts your organization makes towards continual improvement, product/service quality, and customer satisfaction.