CSSGB study guide · 2026

The 6 CSSGB domains, explained

6 domains and 24 official topics. Define Phase carries the most weight at 23%. Each guide explains what the domain covers, how its questions are framed and where candidates lose marks.

Start with Domain 2 See all domains
Questions
110 on computer-based testing (100 scored, 10 unscored); 100 on paper
Time
4 hours 18 minutes (4.5-hour appointment), open book
Passing score
550 out of 750 (scaled)
Outline
ASQ CSSGB Body of Knowledge (2022 version), current as of October 2026

Exam blueprint

Bar widths follow the official weights. Weight ranges are drawn at their midpoint.

  1. 1 13%
  2. 2 23%
  3. 3 23%
  4. 4 15%
  5. 5 15%
  6. 6 11%
  1. 1 Overview: Six Sigma and the Organization
  2. 2 Define Phase
  3. 3 Measure Phase
  4. 4 Analyze Phase
  5. 5 Improve Phase
  6. 6 Control Phase

All 6 domains

24 official topics 105–135 hrs suggested study

  1. Domain 01 13%

    Overview: Six Sigma and the Organization

    This section asks why an organization runs Six Sigma at all: linking projects to strategy, seeing work as a value stream, and knowing when to redesign with DFSS instead of fixing with DMAIC. It frames how every later phase question is judged.

    Inside this domain

    • Six Sigma and organizational goals
    • Lean principles in the organization
    • Design for Six Sigma (DfSS) methodologies

    Watch for Lowest cost project wins

    Topics
    3
    Questions est.
    ~13
    Study time est.
    15–20 hrs
  2. Domain 02 23%

    Define Phase

    The Define phase is one of the two heaviest CSSGB sections. It covers choosing and chartering a project, turning the voice of the customer into measurable requirements, planning tools, the business metrics that justify a project, and leading the team.

    Inside this domain

    • Project identification
    • Voice of the customer
    • Project management (PM) basics
    • Management and planning tools
    • and 2 more topics

    Watch for DPU passed off as DPMO

    Topics
    6
    Questions est.
    ~23
    Study time est.
    25–30 hrs
  3. Domain 03 23%

    Measure Phase

    Measure is the most calculation-heavy CSSGB section and ties with Define as the largest. It covers documenting the process, probability and distributions, collecting and summarizing data, validating the measurement system, and judging capability against specifications.

    Inside this domain

    • Process analysis and documentation
    • Probability and statistics
    • Statistical distributions
    • Collecting and summarizing data
    • and 2 more topics

    Watch for Cp says capable

    Topics
    6
    Questions est.
    ~23
    Study time est.
    25–30 hrs
  4. Domain 04 15%

    Analyze Phase

    Analyze is where a Green Belt proves which inputs drive the problem. It covers exploratory data analysis, the logic and choice of hypothesis tests, and the root cause, gap and waste analysis methods that turn data into a defensible cause.

    Inside this domain

    • Exploratory data analysis
    • Hypothesis testing
    • Additional analysis methods

    Watch for Correlation as causation

    Topics
    3
    Questions est.
    ~15
    Study time est.
    15–20 hrs
  5. Domain 05 15%

    Improve Phase

    Improve turns verified root causes into a tested solution. This section covers designed experiments to find the best settings, planning and piloting the change, and the lean tools that remove waste and speed up flow.

    Inside this domain

    • Design of experiments (DOE)
    • Implementation planning
    • Lean tools

    Watch for No main effect, so no influence

    Topics
    3
    Questions est.
    ~15
    Study time est.
    15–20 hrs
  6. Domain 06 11%

    Control Phase

    Control makes sure the gain from a project lasts. It covers statistical process control to tell common from special cause variation, the control plan and handoff that sustain the improvement, and lean tools such as TPM and visual controls.

    Inside this domain

    • Statistical process control (SPC)
    • Sustain improvements
    • Lean tools for process control

    Watch for np chart with varying samples

    Topics
    3
    Questions est.
    ~11
    Study time est.
    10–15 hrs

Study the heaviest domains first

Marks follow weight. This order puts the most marks behind you first, across about 105–135 hrs of study.

  1. 2 Define Phase 23% · 25–30 hrs
  2. 3 Measure Phase 23% · 25–30 hrs
  3. 4 Analyze Phase 15% · 15–20 hrs
  4. 5 Improve Phase 15% · 15–20 hrs
  5. 1 Overview: Six Sigma and the Organization 13% · 15–20 hrs
  6. 6 Control Phase 11% · 10–15 hrs

Try one

Practice questionDomain 2: Define Phase

An accounts payable team processed 500 invoices last month. Each invoice has 6 fields that can be entered incorrectly, and an audit found 45 incorrect fields in total. What is the DPMO for invoice entry?

One trap from every domain

The answer that looks right, and the clue that gives it away.

  • Domain 1

    Lowest cost project wins

    Clue Look for a stated strategic goal or customer metric in the stem and pick the project that moves it.

  • Domain 2

    DPU passed off as DPMO

    Clue The stem states a number of opportunities per unit, which must appear in the denominator.

  • Domain 3

    Cp says capable

    Clue The mean given is not halfway between the limits.

  • Domain 4

    Correlation as causation

    Clue Observational data and an option that jumps straight to changing the process.

  • Domain 5

    No main effect, so no influence

    Clue Crossing lines on the interaction plot or a large interaction term in the table.

  • Domain 6

    np chart with varying samples

    Clue A stated range of sample sizes, such as 80 to 140 per day.

Other Quality Management certifications

Study guides for exams that overlap with CSSGB.

Practise what you read

CSSGB domains: common questions

How many domains are in the CSSGB exam?

CSSGB has 6 domains with 24 official topics between them: Overview: Six Sigma and the Organization, Define Phase, Measure Phase, Analyze Phase, Improve Phase and Control Phase.

Which CSSGB domain carries the most weight?

Define Phase is the heaviest at 23%, followed by Measure Phase (23%). The lightest is Control Phase (11%). Weights come from ASQ's official outline.

What is the CSSGB exam format?

Questions: 110 on computer-based testing (100 scored, 10 unscored); 100 on paper. Time allowed: 4 hours 18 minutes (4.5-hour appointment), open book. Passing score: 550 out of 750 (scaled).

How long should I study for CSSGB?

Our planning estimate is 105–135 hrs across all domains, split by weight. It is an editorial estimate, not an official figure, so adjust it to your experience and to how you score on practice questions.

Where should I start?

Start with Define Phase, because it carries the most marks, then work down by weight. Use the checklist on each domain page to confirm you can do what the domain asks before moving on.

Which outline is this guide based on?

This guide follows ASQ CSSGB Body of Knowledge (2022 version), current as of October 2026, published by ASQ. It was last reviewed in October 2026.

Domain names, weights and topics come from ASQ's official outline (ASQ CSSGB Body of Knowledge (2022 version), current as of October 2026). Question counts and study hours are editorial planning estimates, not official figures. Last reviewed October 2026.