Other Industry / Management Certifications & Six Sigma
An Organisation being ISO / QS / SEI-CMM / COPC, etc, certified would be having its own way of process/business functions in accordance with the norms laid down by the certifying body (as above). However, acquiring these certifications do not ensure business success/profitability, & are usually an outcome of customer & market expectations, & an endeavor by the certified organization to show its commitment towards the same. Such certified organizations can further move up the growth ladder by use of Six Sigma methodology, which directly links the business improvement efforts (achieved through Six Sigma) with business success & emphasis on continual improvement.
Though, Other Certification programs & Six Sigma do not spell out implicit/explicit dependence on each other, a Six Sigma initiative can be started irrespective of other certifications had/acquired by the organization.