Six Sigma Standards

The ISSP have 6 standards and 4 apprenticeships which companies and individuals can apply to be accredited against.

  • Lean Six Sigma – Yellow, Black and Master Black Belt
  • Six Sigma – Yellow, Black, Master Black
  • Business Improvement Apprenticeships – Levels 3 – 6

Individuals can apply through the contact page of the website and submit supporting information to justify the level they are applying for.

Individuals wishing to apply for Professional level membership will need to submit a PDF portfolio of work including a recent DMAIC project, attached their CV, and proof of Black Belt training, including their certificate, course outline and any exam completed.

Individuals which fail to meet the requirements of the ISSP will be invited to join as a “Member” and given feedback on what is required to meet the “Professional” level and the option to resubmit at a later date

ISSP logo on glass

Fellows are invited to join by the ISSP, profession members are encourage to contact the ISSP directly to request consideration.

There is no additional charge to individuals to gain accreditation if they request accreditation at point of joining. They will be simply charged the fee at the appropriate level requested. Existing members will be charged a second membership fee at the appropriate level if they request certification at a later date or fail to meet the initial requirements of membership.

Companies should first join as an affiliate member and then request application form to gain accreditation against one of the ISSP standards.

Professional applicants are required to demonstrate skills, knowledge and experience in the following areas:

  • Applicants must have completed at least 2 strategically significant business change projects. Evidence required: Summary of 2 projects in the last 18 months.
  • They must have mentored other individuals within their improvement projects. Evidence required: Summary of mentoring given, and references from at least one person mentored.
  • Completion of formal Black Belt training. Evidence required: Summary of course outline and copies of any certificates issued.

Specifically the applicant must demonstrate examples where they:

  • Dealt with non-normal data in appropriate circumstances.
  • Completed measurement systems analysis to improve confidence in data collected.
  • Used advanced statistics, such as hypothesis testing to identify change.
  • Used non-linear regression to build accurate models of processes.
  • Completed design of experiment studies to optimise processes.

The ISSP define a Yellow Belt as an individual who has a good understanding of Lean Six Sigma or Six Sigma; it is general awareness that is useful for those who are not directly involved but will be supporting, sponsoring and resourcing Lean Six Sigma or Six Sigma projects. In certain circumstances they may be encouraged to run their own small projects under guidance and support from and Green or Black Belt professional.

Duration: A typical Yellow Belt programme would last between 1 to 2 days.

Accreditation: No formal assessment is required, however 100% attendance is expected of the training sessions. Optional project activity is also encouraged.

Example Content:

Day 1:

  • Introduction to Six Sigma
  • Define:
  • Project Chart
  • Voice of the customer
  • Process Mapping, spaghetti diagrams, before pictures
  • Measure:
  • Data collection plan
  • Appreciation of graphical and mathematical methods of describing the process


Day 2:

  • Analysis:
  • Variation studies – common cause, special cause, operator, sampling and measurement error
  • Understanding the link between the output (Y) and the inputs (X)
  • Idea generation and brainstorming techniques
  • Prioritisation techniques
  • Piloting solutions
  • Before and after comparisons
  • Control:
  • Control plan
  • Tracking process drift

The ISSP define a Green Belt qualified individual as someone who is able to solve technical and challenging problems through the Lean Six Sigma or Six Sigma method. They can lead projects and support Black Belts as they deliver larger more strategic change.

The main elements of a Green Belt qualification should be the use of DMAIC, using statistics to make better decisions and managing change.
Duration: A typical Green Belt programme: Study time: 5 – 8 days in the class room, plus a minimum of 3 support and mentoring days from a Black Belt while the Green Belt trainees complete their assessment.

Accreditation: Assessment would be through a project, lasting no more than 3 months and deliver significant business improvement. The ISSP does not insist on delegates sitting an exam – however the ISSP have examples of Green Belt tests which can be used to assess training competencies.

Minimum Content: Individuals will be able to understand:

  • Everything within the Yellow Belt programme plus:
  • The principles of Lean Six Sigma and Six Sigma and how it can be used as a powerful business improvement tool.
  • The tools and techniques needed to analysis a value chain, and subsequent process maps.
  • How to use the 7 Quality Tools to challenge and improve the status quo.
  • The concepts needed to make change stick.
  • The power of software to simulate processes and improvement opportunities.
  • Basic well known Six Sigma statistical tools such as hypothesis testing, linear regression and simple full factorial design of experiments (DoE).


Example Content:
Typically Green belt programmes are delivered in 3-4 blocks of 2-3 days.

Part 1:
Introduction to Six Sigma
Define: Project charters, project management techniques, voice of the customer, critical to quality, cost of poor quality, kano model, SIPOC, process mapping, X&Y, spaghetti diagrams, cause and effect matrix
Measure: Types of data, shape of distributions, sampling strategies, measurement systems analysis, gauge R&R studies, measures of variation, and measures of central tendency

Part 2:
Analysis: 5 whys, root cause analysis, fish bone diagrams, process capability, cpk/ppk, DPMO, sigma benchmark, yield, process stability studies, non-normal data strategies, hypothesis testing

Part 3:
Improve: Lean tools, process modelling, correlation and regression, design of experiments, brain storming, prioritisation and demonstrating change
Control: Control plans Engineering fixes, Documentation updates, training an development, measurement of drift, and change management

Both Yellow Belt and Green Belt trained individuals are entitled to join the Institute of Six Sigma Professionals (ISSP) as a Member.

A qualified Black Belt, as defined by ISSP, will not only know the topics listed above and be able to apply Six Sigma, but will also be able to manipulate the methods in order to be successful in different circumstances.

Individuals with this level of knowledge will be able to select the most appropriate method depending on the situation. They will be able to generate innovative and creative ways to solve complex challenges. They are expected to be able to champion and lead continuous improvement in their organisation and train and develop staff internal to at least Green Belt standard.

Duration: A typical Black Belt programme: Study time: 20 – 25 days in the class room, plus a minimum of 6 support and mentoring days from a Master Black Belt.

Accreditation: Assessment would be through a minimum of 2 strategically important projects, each lasting no more than 6 months and delivering significant business improvement. In addition delegates are required to pass an exam which is designed to test the delegates on their academic and theoretical knowledge of six sigma.

Minimum Content: Black belt programmes are required to challenge the delegates in three areas: Leadership, Programme Management and Advance Statistics.

Example Content:
Black belt programmes are best delivered over a 3 month period, in blocks of 4-5 days. By the time delegates complete the class room activity they will need to understand everything at Green Belt standard, and:

  • The DMAIC and other continuous improvement approaches, such as Systems Thinking, Lean and Theory of Constraints
  • Project selection, management and stakeholder analysis.
  • How to lead and implement a continuous improvement culture within their organisation
  • Alternative process mapping and modelling techniques
  • Use statistical software such as Minitab.
  • Advanced process capability studies, non-normal capability studies, Binomial and Poisson studies.
  • Measurement systems analysis, bias and linearity.
    Measuring the cost of poor quality.
  • Hypothesis testing – normal and non-normal, continuous and discrete data.
  • Confidence intervals, correlation, non-linear regression and non-linear regression analysis and modelling.
  • Multi-variance studies.
  • Advanced DoE techniques, including Reverse DoE, Response Surface Methodology.
  • FMEA, Mistake Proofing Advance process stability and control charting.

Individuals who meet the above criteria may apply to become a Professional member of the Institute of Six Sigma Professionals

The final level of Six Sigma is a Master Black Belt. ISSP characterises this as an individual who, after gaining Black Belt status, has:

  • Evidence of continuous personal development. They should be able to show they have had at least two years experience of continuous project work. They should also be seen to be attending conferences and seminars to continually develop their skills within the Lean Six Sigma or Six Sigma field.
  • Mentored and supported Yellow, Green and Black Belts within their organisations and/or consultancy projects.
  • Been involved with the training, or at least the steering of training, of lower levels.
  • Have significant sector experience within their chosen field and a minimum of 2 years’ service delivering projects within the sector

In order to become a Fellow of the Institute of Six Sigma Professionals, an individual must go through the ISSP Accreditation Unit. They will need to prove they have developed a discipline and practice in the field, and pushed boundaries within Six Sigma. Essentially, they should be “ambassadors” for the subject within their sector or organisation, for example, written articles or books, given speeches etc. They should also be able to provide a Personal Development Record proving their knowledge, achievements and improvements over many years. Specifically:

  • Applicants must have developed significant business improvement knowledge, skills and behaviours in a variety of business improvement disciplines, such as LEAN, Theory of Constraints, PRINCE2 etc. Evidence required: Summary of projects and training certificates.
  • Delivered training for, and mentored, both black and green belts within their organisation. Evidence required: Summary of training and mentoring delivered, plus references from those mentored.
  • Have gained at least 2 years industrial sector experience at black belt level. Evidence required: Up to date CV.
  • Have maintained both a professional and development record over the past 2 years, examples include updating skills to meet the rapid advances of computer processing power to perform complex data analysis, attending networking and conference events, witting research papers on six sigma tool development. Evidence required: CPD record.

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