Why do many organizations with Lean Six Sigma initiatives still struggle during an ISO 18404 audit?
The issue often isn’t with tools like DMAIC or process mapping — it’s a lack of formal structure, documented competence, and role clarity as defined by the ISO 18404 framework.
This guide was developed in collaboration with insights from over 100 certified ISO 18404 Lead Auditors, including subject matter experts affiliated with global certification bodies such as GSDC.
Part of our ISO Survival Kit series, this resource is designed to support organizations working toward ISO 18404 Lead Auditor certification or conducting internal assessments using an ISO 18404 checklist.
Whether you’re enrolling in an ISO 18404 course, developing an internal audit strategy, or leading a continuous improvement office, this guide delivers practical value from the field.
It’s also ideal for professionals undergoing ISO 18404 training and preparing for the auditor’s perspective — from Lean Practitioners and Six Sigma Belts to Improvement Leaders and quality managers.
📌 Clause: 5.3 – Competence of Individuals
What’s Going Wrong:
Organizations assign titles like Lean Practitioner, Six Sigma Green Belt, or Black Belt without validating whether individuals actually possess the competencies required by ISO 18404. Roles are often self-proclaimed or based on outdated training without assessment.
Why It Matters During an Audit:
ISO 18404 distinguishes specific competency levels for Practitioners and Improvement Leaders. Auditors expect documented evidence that individuals performing these roles meet the required standards through structured assessment, not just job titles.
How to Fix It:
✔ Implement a role-specific competence matrix aligned with ISO 18404
✔ Conduct assessments or use certified evaluators to validate practitioner competence
✔ Maintain records of assessments, evaluations, and certification outcomes
✔ Link certification to your ISO 18404 training or internal development programs
Real-World Result:
Clear, auditable competence frameworks boost credibility with auditors and build internal consistency in project execution.
📌 Clause: 5.2 – Organizational Readiness
What’s Going Wrong:
Organizations initiate Lean or Six Sigma programs without defining governance structures, allocating budgets, or supporting roles like Improvement Leaders. Projects are isolated, with little alignment to broader business systems.
Why It Matters During an Audit:
ISO 18404 evaluates not just individual roles but also whether the organization has the infrastructure to sustain improvement. Auditors look for defined processes, leadership involvement, and system-level support for project selection, tracking, and results.
How to Fix It:
✔ Define an improvement governance framework (roles, processes, reviews)
✔ Appoint executive sponsors and allocate cross-functional resources
✔ Integrate Lean Six Sigma into the management system
✔ Include improvement metrics in strategic dashboards
Real-World Result:
An established structure ensures improvement isn’t siloed and shows auditors that capability is embedded across functions.
📌 Clause: 5.1 – Strategic Alignment
What’s Going Wrong:
Many organizations run improvement projects without a guiding strategy. There's no clear link between LSS initiatives and business objectives and no roadmap for capability development or
performance goals.
Why It Matters During an Audit:
ISO 18404 requires that Lean and Six Sigma be tied to strategic objectives. Auditors want to see documented alignment that guides prioritization, resourcing, and long-term capability development.
How to Fix It:
✔ Create a documented LSS deployment strategy aligned with organizational goals
✔ Include targets for capability building, project selection, and performance improvement
✔ Review strategy annually with leadership input
✔ Tie LSS outcomes to business KPIs
Real-World Result:
A strategic plan turns improvement into a scalable, sustainable advantage that satisfies both operational and audit expectations.
📌 Clause: 5.3 – Competence of Individuals
What’s Going Wrong:
Training is generic or based on commercial certifications that don’t match ISO 18404's defined role expectations. There's no assurance that participants are trained to the required depth or assessed effectively.
Why It Matters During an Audit:
Auditors expect that Lean and Six Sigma training is tailored to the ISO 18404 framework. Without alignment, training programs are deemed non-compliant, and roles may be invalidated.
How to Fix It:
✔ Redesign your ISO 18404 course content around the standard’s specific competencies
✔ Use defined learning outcomes, practical exercises, and exams for each role level
✔ Deliver training through accredited instructors or aligned programs
✔ Tie training completion to competence validation
Real-World Result:
Aligned, assessed training ensures participants meet global standards and prepares organizations for robust certification audits.
📌 Clause: 5.3.2 – Lean and Six Sigma Practitioners
What’s Going Wrong:
Project teams include individuals labeled as practitioners, but there is no documented proof they’ve been evaluated against the ISO 18404 competency model.
Why It Matters During an Audit:
ISO 18404 requires evidence that those performing LSS roles meet prescribed knowledge and skill criteria. Lack of formal validation raises concerns about consistency and quality of delivery.
How to Fix It:
✔ Introduce formal evaluation (written, oral, and practical) for all Lean and Six Sigma practitioners
✔ Create or adopt an internal certification scheme mapped to ISO 18404
✔ Maintain a certification registry, including role type, assessment date, and evaluator name
Real-World Result:
Internal certification linked to ISO 18404 builds credibility with auditors and promotes real practitioner competence.
📌 Clause: 5.3.3 – Improvement Leaders
What’s Going Wrong:
The role of the Improvement Leader is misunderstood or undefined. Often, senior managers assume they fulfill the role without formal training or involvement in project governance.
Why It Matters During an Audit:
ISO 18404 defines Improvement Leaders as distinct from Belts — with responsibilities including strategic deployment, mentoring, and program oversight. Auditors expect to see training, experience, and structured engagement at this level.
How to Fix It:
✔ Identify Improvement Leaders formally within your structure
✔ Provide targeted training focused on deployment, coaching, and strategic alignment
✔ Involve them in project selection, reviews, and resource allocation
Real-World Result:
Leadership roles become active drivers of improvement, reinforcing cultural change and meeting certification expectations.
📌 Clause: 9.2 – Internal Audit
What’s Going Wrong:
Organizations run audits using general quality management checklists that overlook Lean and Six Sigma role competencies, project validation, or strategic alignment.
Why It Matters During an Audit:
Internal audits must reflect the unique structure of ISO 18404 — assessing both individual competencies and the system’s support for improvement. An incomplete audit process leads to repeat non-conformities.
How to Fix It:
✔ Develop a clause-by-clause ISO 18404 checklist for internal audits
✔ Include project documentation review, role competence, and alignment to strategy
✔ Train internal auditors specifically on the ISO 18404 framework
Real-World Result:
Effective internal audits uncover real gaps, support ongoing improvement, and prepare teams for external certification success.
📌 Clause: 6.1 – Lean Methodologies
What’s Going Wrong:
Lean is implemented loosely or through tool-based activity (like 5S), with no defined methodology or standard project structure. Documentation is inconsistent or missing.
Why It Matters During an Audit:
ISO 18404 expects recognized Lean methods to be applied systematically — from root cause analysis to implementation and sustainability planning.
How to Fix It:
✔ Standardize Lean methodologies across the organization (e.g., A3, Kaizen, PDCA)
✔ Train teams on structured problem-solving and documentation practices
✔ Require documented deliverables and project tracking
Real-World Result:
Consistent, methodical Lean practices enhance effectiveness and meet auditor expectations for structured implementation.
📌 Clause: 6.2 – Six Sigma Methodologies
What’s Going Wrong:
Six Sigma projects rely on spreadsheets and intuition rather than statistically sound tools. There’s little evidence of hypothesis testing, process capability analysis, or proper control planning.
Why It Matters During an Audit:
ISO 18404 calls for the application of proven Six Sigma techniques in a structured, evidence-based manner. Failure to apply the methodology correctly weakens the credibility of project outcomes.
How to Fix It:
✔ Adopt statistical tools like Minitab or JMP
✔ Train Belts on analytical techniques (e.g., regression, DOE, control charts)
✔ Include statistical validation in project tollgates and reviews
Real-World Result:
Auditable, statistically sound projects demonstrate mastery of methodology and data-driven improvement.
📌 Clause: 7.1 – Performance Measurement
What’s Going Wrong:
Project teams celebrate completion but don’t track whether promised cost savings, defect reduction, or lead time improvements are realized and sustained over time.
Why It Matters During an Audit:
ISO 18404 emphasizes performance — not just activity. Auditors expect quantitative evidence that projects deliver and sustain business impact.
How to Fix It:
✔ Measure KPIs before, during, and 6–12 months after project closure
✔ Build benefit realization into the control phase
✔ Report results to leadership and integrate findings into future project planning
Real-World Result:
Demonstrating results builds confidence in your Lean Six Sigma system and delivers a powerful case for ISO 18404 certification.
This guide consists of the complete collection of 100 failures experienced during the ISO 18404:2015 audit, each supported by audit evidence and clause-wise guidance. Download the checklist for the following benefits:
Ready to close your Lean Six Sigma compliance gaps?
This guide consists of the complete collection of 100 failures experienced during the ISO 18404:2015 audit, each supported by audit evidence and clause-wise guidance.
It has drawn insights from more than 100 certified ISO 18404 Lead Auditors and serves as a complete manual for certification success.
Whether you're refining your internal ISO 18404 checklist, managing a Lean Six Sigma deployment, or supporting professional development through an ISO 18404 course, this guide delivers actionable tools to boost your audit readiness.
ISO 18404:2015 is undoubtedly a standard, but it is also a defined framework for systematic, role-based improvement across your organization.
When auditing for the most commonly experienced non-conformities, you are not only remediating compliance issues but also building leadership, proving practitioner competence, and embedding a high-performance culture.
To thrive under ISO 18404, organizations must:
Use this guide to elevate your program from informal to audit-ready and turn certification into a strategic differentiator.
Stay up-to-date with the latest news, trends, and resources in GSDC
If you like this read then make sure to check out our previous blogs: Cracking Onboarding Challenges: Fresher Success Unveiled
Not sure which certification to pursue? Our advisors will help you decide!
