Don’t understand basic Lean 6S interview questions?
You won’t get the job.
Think companies such as Ford, Toyota, GM, 3M, GE, Amazon, and tons more companies.
Any company that does high scale production will utilize Lean 6S to streamline manufacturing.
They don’t do it because they want to, they do it because they have to.
Companies need to make money and to do so, they need to implement Lean 6S.
If you’re interviewing for a job that requires lean, make sure to have an understanding of these lean 6S Interview Questions.
April 11, 2025 by Kazu Fujimoto
The following questions are basic concepts that you will go over in a Lean 6S manufacturing environment.
Make sure you know these questions both so that you are ready for an interview and you also will need to know these terms if you want to be a good engineer that can implement lean.
Book a technical mock interview with Kazu to 10X chances of landing the engineering job.
What is Lean Six Sigma?
Lean Six Sigma combines Lean and Six Sigma to improve processes by enhancing efficiency and quality.
- Lean focuses on eliminating waste (e.g., excess inventory, unnecessary steps) to streamline operations and deliver value to customers faster.
- Six Sigma aims to reduce process variation and defects using data-driven tools and statistical analysis, targeting near-perfect quality (fewer than 3.4 defects per million opportunities).
The “6S” refers to an extension of Lean principles: Sort, Set in Order, Shine, Standardize, Sustain, Safety, which organizes workplaces for efficiency and safety, complementing Lean Six Sigma goals.
What is the Lean Methodology?
The Lean methodology is based on five core principles that guide organizations to deliver value efficiently by eliminating waste and optimizing processes.
1. Define Value – Identify what the customer truly values in your product or service (e.g., quality, speed, cost). This sets the foundation for all improvements, ensuring efforts align with customer needs.
2. Map the Value Stream – Analyze the entire process (from raw materials to delivery) to map all steps that create value. Highlight and eliminate waste—activities that don’t add value, like waiting or excess inventory. (Value stream mapping)
3. Create Flow – Ensure the process runs smoothly without interruptions or bottlenecks. Streamline steps, balance workloads, and remove delays to make value flow seamlessly to the customer.
4. Establish Pull – Produce only what the customer demands, when they demand it, to avoid overproduction. Use systems like Just-in-Time to align production with actual need, reducing waste and inventory.
5. Pursue Perfection – Strive for continuous improvement (Kaizen) by relentlessly refining processes. Encourage teams to identify and solve inefficiencies, aiming for zero waste and optimal performance.
These principles, derived from Toyota’s production system, work together to maximize customer value while minimizing resources.
What is 6S?
6S is a workplace organization methodology that builds on the Lean 5S system by adding a sixth element, Safety. It aims to create an efficient, organized, and safe work environment to support Lean principles and continuous improvement.
The six components are:
- Sort (Seiri)
- Set in Order (Seiton)
- Shine (Seiso)
- Standardize (Seiketsu)
- Sustain (Shitsuke)
- Safety
What is Sort?
Sort is a principle based on removing unnecessary items from the workplace, keeping only what’s needed for daily tasks to reduce clutter and waste.
What is Set?
Set is a principle based on arranging tools, materials, and equipment logically for easy access, often using labels, color-coding, or designated spots to save time and improve workflow.
What is Shine?
Shine is a principle based on keeping the workplace clean and tidy through regular cleaning and maintenance to ensure equipment reliability and a professional environment.
What is Standardize?
Standardization is a principle based on the creation of consistent procedures and visual guides such as checklists and schedules to maintain the first three S’s and ensure everyone follows the same practices.
What is Sustain?
Sustain is a principle based on building a culture of discipline to maintain 6S practices through training, audits, and ongoing commitment to prevent backsliding, schedule delays, and quality defects.
Why is safety important?
Safety protects employees, reduces accidents, improves productivity, and is an overall good for the company.
Can you share an example of a Lean Six Sigma project that you’ve worked on?
Use the STAR format to talk about a project, the problem, what you did, the tools and methodologies used and what the measurable outcomes were.
Have you implemented 6S in a workplace?
Use a specific example tailoring to your experience such as organizing a workspace, removing clutter, reducing waste, or improving safety and explain the impact. Highlight results such as reduced downtime and errors.
What tools or techniques do you use in Lean 6S Projects?
Identify the job description that you’re applying for and list any one of these as applicable:
- Process maps
- Fishbone diagrams
- Pareto charts
- 5 Whys
- Statistical analysis
- Control charts
And explain each use and what you did to overall implement lean.
How would you ensure the “Sustain” aspect of 6S is maintained?
Discuss strategies such as regular audits, training, visual management, or employee engagement (monitor as a metric) to keep 6S practice consistent.
How do you identify waste in a process?
Reference the 8 wastes as stated in the TIMWOODS acronym:
- Transform
- Inventory
- Motion
- Waiting
- Overproduction
- Overprocessing
- Defects
- Skills
And how you would analyze a process to spot them.
What would you do if faced with some resistance from colleagues or leadership to implement 6S changes?
Talk about how you’d present and sell the benefits to the team and identify that if the respective 6S changes won’t be made, the company will lose money through waste, errors, or defects.
How would you know which processes to improve using Lean Six Sigma?
Explain the impact on customers, frequency of issues, cost savings, or how it aligns with current company business goals. Use tools such as a CTQ (Critical to Quality) tree.
How would you include your team in a Lean 6S initiative?
Discuss creating workshops, events, hosting presentations and drive the importance of continuous improvement.
What role does leadership play in the success of Lean Six Sigma?
Discuss how leaders set the vision framework in place and process improvement will occur as a downstream impact through resource allocation, model behaviors, and sustaining momentum.
How would you train others on complex 6S ideologies?
Share how you would break down complex ideas using hands on exercises catered to different roles. Different roles would be those working on the shop floor vs. those working in management or leadership.
How do you measure the success of a 6S or Lean Six Sigma project?
Talk about how you would track KPIs such as cycle time reduction, defect rates, cost savings, or employee satisfaction and how you track them through tools such as control charts or dashboards.
What’s the difference between a process capability index (Cp/Cpk) and sigma level?
Explain Cp/Cpk as measures of process capability and sigma level as a measure of process performance relative to defects.
How do you ensure improvements from a 6S initiative are quantifiable?
Talk about how you would set baseline metrics before starting such as time to complete the task and comparing them to post implementation. Before and after results using tools such as charts and dashboards are great.
Tell me about a time when a Lean Six Sigma project didn’t go as planned.
Use the STAR format and share a challenge that you had, how you addressed it, the tools you used, and what happened as a result.
What would you do if a team member wasn’t following 6S standards?
Use a constructive approach by understanding their perspective, reinforcing the benefits, provide coaching and support as needed, and keep a consistent eye on progress. Set up discussions and escalate to leadership as needed.
How do you balance the need for quick wins with long-term Lean Six Sigma goals?
Do a comparison between “low-hanging fruit” to build momentum while keeping the high level in focus.
Additional Tips and Insight on Lean 6S Interview Questions
Understand your specific projects. Be ready to be able to discuss examples with results and be able to quantify them (Ex. Reduced defects by 69%)
Understand what each of the specific tools that Lean 6S run on.
Use the STAR format when interviewing.
Tailor your answers to the job description that the role provides. Hiring managers will be focused on some of the key words pertaining to the role.
Book a technical mock interview with Kazu to 10X chances of landing the engineering job.
Our mock interviews break up behavioral and technical step by step and as a result will prepare you for challenging interviews.
About the author
Kazuyoshi Fujimoto, PE
Founder | Engineering Career Coach | Principal Mechanical Engineer
Kazu oversees all of ultmeche’s engineering services. He provides consulting such as resume reviews, rewrites, mock interviews, and all services career related. Additionally, Kazu performs consulting work regarding Oil & Gas, Automotive, and Aerospace & Defense. Kazu is licensed as a professional engineer in the state of California and has 9+ years of experience in Oil & Gas, Automotive, and Aerospace & Defense.