RSS 18404

The only route for certification against IS0 18404:2015

ISO 18404:2015 is the international standard for quantitative methods in process improvement and competencies for key personnel and their organisations in relation to Six Sigma and Lean implementation.

As both systems have been in use for some years, a global view on the competence requirements for people delivering Six Sigma projects and Lean improvement, and the requirements for organisations managing them, was overdue. ISO 18404, launched in 2015, is that international standard.  

Now for the first time, organisations in the UK can be certified against ISO 18404 through the Sector Scheme, called RSS 18404.  The RSS 18404 Sector Scheme is the only way organisations and individuals can be certified against ISO 18404 in the UK. Thus RSS 18404 provides a level of assurance on the skills of certified Six Sigma and Lean professionals and on best practices at an organisational level not previously available. A copy of the Sector Scheme RSS 18404 can be downloaded here.

The Royal Statistical Society (RSS) is the owner of the Sector Scheme, as both Six Sigma and Lean use statistical and data tools, and statistics underpin these process improvement methodologies. The RSS is responsible for the Sector Scheme’s overall operation, including

  • the qualification and monitoring of participating Certification Bodies (who carry out the audits and certify organisations)
  • maintaining a register of those approved Certification Bodies
  • training and certifying Certification Bodies’ Lead Auditors
  • running assessment centres for individuals wishing to be RSS 18404 certified at any level (Green Belt to Master Black Belt or Lean Practitioner to Lean Expert)
  • running training courses to prepare individuals for assessment centres
  • maintaining a register of all assessed competent personnel (whether assessed by us or by the certified organisations) and certified organisations
  • maintaining a list of approved training courses for individuals interested in certification

For the first time, organisations can now gain certification to ISO 18404.  Contact your Certification Body or click here to find out more.

If you’re a Lean/Six Sigma practitioner, or you want to start gaining those skills, you can also now gain certification as an individual. Take a look at our training courses or find out more here

For Certification Bodies who wish to participate in RSS 18404, please get in contact with Stuart McKendrick ( or find out more here.