Lean Six Sigma Green Belt Interview Questions and Answers for Quality Management Mastery

Modern-day businesses at the forefront are governed by speed, efficiency, and quality. Quality refers to maintaining good standards of production while speed implies timely delivery of the product. Efficiency is needed at all stages starting from the manufacturing inputs to the desired results. The most able-handed personnel for accomplishing these organizational goals are the ones who possess Lean Six Sigma Green Belt Certification. They are empowered to take on head-on challenges, identify opportunities, and solve problems. Green Belt is a level of expertise in Lean Six Sigma to help organizations achieve their end objectives.

Based on team collaboration, Lean Six Sigma certainly supports the involvement of employees in waste removal from business procedures. It emphasizes the prevention of defects rather than detecting them. Certified individuals optimize the collected data to analyze faults. The skills obtained through Lean Six Sigma Training apply to organizations irrespective of their sizes or industries. Profitability and cost-effectiveness are the breakthroughs that Lean Six Sigma Certification Green Belt holders bring to businesses. Given below are the questions that individuals can expect during their interviews for landing quality management or relevant job.

Universally applicable to most projects across organizations, Lean Six Sigma principles are centered around problem-solving. Enterprises can detect the origin of problems along with the expenses following them. Thus, these techniques help them reach solutions to operational issues through suitable precautionary and cost-curtailing measures. In other words, Lean Sigma is a business process-enhancing methodology.

Lean comprises principles for making smarter business decisions while Six Sigma encompasses the techniques to detect and eradicate problems. A combination of Six Sigma and Lean proves fruitful. The former focuses on variability reduction for waste removal while the latter emphasizes improvement in procedures for high consumer value.

Lean Six Sigma Green Belt Certification holders are adept at maintaining project budgets to ensure a business’s cost-effectiveness. They assist organizations to do away with reserve funds. Detection of problems at their initial stages results in project completion without exceeding its expenses. Optimization of consumer feedback and increased profitability are the other contributions of certified individuals that are significant in curbing costs.

Lean Six Sigma Green Belt Certification holders assist enterprises in providing the best-quality services and products at the consumers’ service. Naturally, customers begin to trust such organizations and become their loyal audience.

Wastage regarding inventory, transportation, waiting, over-production, extra-processing, non-utilized talents, motion, and merchandise. These are the eight types of waste removal responsibilities of individuals possessing Lean Six Sigma Green Belt Certification.

The best part of a Lean Six Sigma project is its systematic execution through a series of steps. Each of these steps is targeted towards a specific value. These values collectively lead to the desired result. Lean Six Sigma Green Belt Certification holders are adept at implementing both statistical and empirical methods.

‘D’ refers to elucidating the project objectives, organizational system, and consumer demands. ‘M’ indicates the measurement of the existing operational procedures’ aspects. It involves relevant data collection which is referred to as ’Process Capability’ calculation. ‘A’ stands for data analysis to confirm the cause-effect relationships. Lean Six Sigma Green Belt Certified individuals reach the prime cause of operational hitches through investigation during this phase. The improvement of existing procedures is referred to as ‘I’ while ‘C’ symbolizes the control over target deviations to prevent future defects.

DMADV refers to the development of new products or processes that cater to the Lean Six Sigma quality standards. On the other hand, DMAIC focuses on the existing procedures to offer incremental improvement.

The basics of Lean Six Sigma are as follows:
  • Customers’ requirements prioritization.
  • Identification of the major reasons for variations in procedures.
  • Proactive reduction of variation.
  • Team formation through engaging an organization’s employees.
  • Flexible, structured, and scientific approach to solving problems.

The scatter plot, control chart, checksheet, Ishikawa diagram, flow chart, histogram, and Pareto chart, are a few of the tools. These tools help in making fact-based decisions for running a successful production cycle. Careful measurements through the use of these tools detect even the minutest flaw.

A Lean Six Sigma Green Belt Certification holder is eligible for leading a project that uses this methodology. He/she is responsible for refining the project charters. Certified individuals also conduct data analysis, detect problems, and organize meetings to report and resolve them.

Lean Six Sigma is based on the following techniques:
  • Five S system
  • Value stream mapping
  • Benchmarking
  • Consumer feedback analysis
  • Poka yoke
  • The 5 why’s
  • Brainstorming

SIPOC is a Lean Six Sigma tool that focuses on the various elements of a business. These include consumers, suppliers, processes, inputs, and outputs. SIPOC is used to evaluate a project’s scope before its beginning by considering the aforementioned components. These factors determine a project’s success to a great extent.

Ishikawa diagram is efficacious in categorizing a project’s failures or issues. In other words, it is a fishbone diagram that was invented by Kaoru Ishikawa. This tool is a visual presentation of the relationship between causes and their corresponding effects and proves effective in problem-solving.

The letters in the acronym FMEA denote the following:
  • F- stands for failure and its detection.
  • M- stands for a mode of failure. This stage involves risk assumption.
  • E & A - indicate the effect of the risk and its analysis.

The aim of using Lean Six Sigma in quality management is to keep variances in processes at bay Certified Lean Six Sigma Green Belt holders gain excellent command of the multiple tools and concepts of this methodology. These tools help in discovering and removing wastes from manufacturing processes.

COPQ(Cost of Poor Quality) is the result of defective operational procedures especially, during production. It is an output of the following factors that Lean Six Sigma Green Belt Certified individuals take care of:
  • Revenue/sales loss
  • Costs of extra material
  • Disposition and reworking expenses
  • Costs resulting from lost opportunities
  • Expenses related to extra utilities and labor
Problem detection and prevention expenses aren’t included in COPQ.

DMAIC involves the Definition, Measurement, Analysis, Improvement, and control of processes. Certified Lean Six Sigma Green Belt holders maintain accounts of measurement values in a process to utilize it for benchmarking. Various quality control tools are available to use the appropriate ones for determining flaws in a specific procedure. Then they concentrate on finding solutions to those flaws. Lastly, they keep the reoccurrence of such issues in check with the help of control measures.

Yes, it is. An affinity diagram is used for the subcategorization of project ideas into clusters. These ideas are the outputs of the brainstorming sessions. They are targeted toward the assessment of complex issues.

Lean Six Sigma secondary and primary metrics are a project’s success indicators. The business goal-oriented processes are measured with the help of primary metrics. The parameters mainly relate to project defects and time of completion. Secondary metrics are used to acquire a picture of the overall project execution.

The SMART model is ideal for implementing metrics in a Lean Six Sigma project. It aims to make business procedures exclude any negative action to meet business goals. This methodology advocates the use of time-based, relevant, achievable, specific, and measurable procedures.

One may conduct load testing separately or under performance testing. This is a test to assess the operating capacity of a system. On the other hand, performance testing evaluates the system’s reliability and responsiveness under an immense workload.

Depending on the project requirement, Lean Six Sigma Green Belt Certified individuals deploy the nominal group technique. The majority’s opinion is taken into account for project defect identification. It is a decision-making method for the members of a Lean Six Sigma project.

Scatter plot diagrams are used as one of the Lean Six Sigma tools. It helps in the faster identification of negative or positive correlations of disparate variables. The vertical and horizontal axes represent dependent and independent variables, respectively.

Projects related to new process designing, process improvement, and new infrastructure implementation. These fall within the Lean Six Sigma project types which call for Green Belt Certification holders.

The Pareto Principle is named after economist Vilfredo Pareto. According to the principle, there is an unbalanced relationship among inputs and outputs, with 80% of the consequences resulting from 20% of the causes.

The Pareto Principle can be applied in a wide range of industries. It includes business, time management, human resources, inventory management, manufacturing, financial management, and healthcare.

Stakeholders are classified into one of four categories:
  • Stakeholders who have high influence and are supportive of the project
  • Stakeholders who have high influence and are not supportive of the project
  • Stakeholders who have low influence and are supportive of the project
  • Stakeholders who have low influence and are not supportive of the project

  • Mean: the arithmetic average of all data points in the data set
  • Median: the middlemost data point in the data set
  • Mode: most frequently occurring data point in the data set
  • Range: the difference between the largest and smallest values in the data set

Lean Six Sigma Green Belt professionals conduct stakeholder analysis during the early stages of the project. They conduct this analysis at regular intervals to understand the current status of the project. Furthermore, shows how stakeholders evolve as the project moves forward and highlights any areas where stakeholder strategies need to be updated.

Poka-yoke is the technique used for avoiding simple human errors at work. It entails creating a procedure that allows to either completely prevent errors or make evident for quick rectification. Poka-yoke reduces waste by getting rid of or cutting down on quality errors that result in scrap and rework.

The three main types of poka-yoke are
  • Contact method
  • Fixed-Value method
  • Motion-step method

The principles of Mistake-proofing are
  • Elimination
  • Prevention
  • Replacement
  • Facilitation
  • Detection
  • Mitigation

5s is used to create a workplace suited for visual control and lean production. It provide a methodology for organizing, cleaning, developing, and sustaining a productive work environment. The 5S pillars are Sort (Seiri), Set in Order (Seiton), Shine (Seiso), Standardize (Seiketsu), and Sustain (Shitsuke).

Take out any trash from the workspace, use 5S red tags to dispose of outdated or damaged parts; ethically recycle materials and papers; keep the workplace from being overloaded with extra stuff; and make an overflow room for extra tools, components, and supplies beyond the workspace.

Six Sigma metrics are a standard set of measurements that organizations may use to monitor the quality of their processes. It aids businesses in increasing process efficiency by reducing waste, cycle time, and failure rates.

There are four types of costs associated with quality
  • Internal failure cost
  • External failure cost
  • Prevention cost
  • Appraisal cost

Prevention costs are the costs incurred to prevent poor quality from occurring in the first place. These expenses are intended to keep the caliber of goods and services from subpar. This cost of quality is associated with the implementation, design, and maintenance of the quality management system.

Standard deviation measures variance the most accurately reflecting the level of variation in a set of measurements or a process or by measuring the average spread of data around the mean. A low standard deviation means data are clustered around the mean, and a high standard deviation indicates data are more spread out.

Testing a system's behavior under an expected load is known as load testing. It aids in determining whether the application is capable of handling a specific limitation. During load testing, all of the system's reaction time, stability, and reliability statistics are gathered. The data is then analyzed to identify any differences.

In the Improve phase of DMAIC, potential solutions are generated and evaluated. The focus is on implementing changes that address the root causes identified in the previous phase and to make the process more efficient, effective, and capable of meeting customer requirements.

There are three pillars in Kaizen
  • Housekeeping
  • Elimination of waste
  • Standardization

The first and foremost step is to have a clear project definition and engage Stakeholders in the project. Professionals then need to gather pertinent data and make decisions based on those facts. The project should have effective project management to ensure that the project moves forward without hiccups. Lastly, the organization should have a continuous improvement culture that supports the added value achieved by Six Sigma initiatives.

MSA refers to Measurement System Analysis, a systematic evaluation and analysis of the measurement system used to collect data. MSA ensures that the data obtained from measurements is accurate, reliable, and consistent.

The tools of Kaizen are
  • Poka-Yoke
  • 5S
  • Value Stream Mapping
  • JIT
  • Kanban
  • PDCA Cycle
  • Gemba Walk

The following are the key roles of Six Sigma:
  • Sponsor
  • Champion
  • Process Owner
  • Master Black Belts
  • Black Belts
  • Green Belts

The two main Six Sigma methodologies are DMAIC and DMADV
  • DMAIC: Define, Measure, Analyze, Improve, Control
  • DMADV: Define, Measure, Analyze, Design, Verify

The Kano Model categorizes customer preferences into the following categories:
  • Basic
  • Performance
  • Excitement
  • Indifferent
  • Reverse

Type I error occurs when a null hypothesis (H0) is incorrectly rejected when it is, in fact, true. It is represented by the symbol α (alpha), which is the significance level or the probability of making a Type I error. While, Type II error occurs when a null hypothesis (H0) is not rejected when it is actually false. Type II error is denoted by the symbol β (beta), which represents the probability of making a Type II error.

  • Six Sigma White Belt
  • Six Sigma Yellow Belt
  • Six Sigma Green Belt Certification
  • Six Sigma Black Belt Certification
  • Six Sigma Master Belt Certification
  • Six Sigma Master Black Belt
  • Six Sigma Champion