What is Lean Six Sigma?

Lean Six Sigma is a methodology that combines the principles of Lean and Six Sigma to improve business processes by eliminating waste and reducing variability. This approach is widely applied across various sectors to enhance efficiency, improve quality, and maximize customer satisfaction. It provides organisations with a set of tools to streamline workflows, minimize errors, and foster a culture of continuous improvement. Additionally, it offers a structured approach to addressing organisational problems and optimizing processes over time.

While Six Sigma focuses on reducing process variation and enhancing process control, lean drives out waste (nonvalue-added processes and procedures) and promotes work standardization and flow. The distinction between Six Sigma and lean has blurred, with the term lean Six Sigma (LSS) being used more often because process improvement often requires aspects of both approaches to attain positive results.

Lean and Six Sigma both provide customers with the best possible quality, cost, and delivery. There is a great deal of overlap between the two disciplines, but they approach their common purpose from slightly different angles:

• Lean focuses on waste reduction, whereas Six Sigma emphasizes variation reduction.
• Lean achieves its goals using less-technical tools such as kaizen, workplace organisation, and visual controls, whereas Six Sigma tends to use statistical data analysis, design of experiments, and statistical process control.
• Successful implementation often begins with the lean approach, making the workplace as efficient and effective as possible by reducing waste and using value stream maps to improve understanding and throughput. If process problems remain, more technical Six Sigma statistical tools may be applied.

The origins of Lean can be traced back to the Toyota Production System, developed in Japan in the 1950s. This system focused on eliminating waste and creating value for customers. By carefully analyzing processes and removing inefficiencies, Toyota managed to produce significantly more efficiently than traditional manufacturers.

Six Sigma was introduced in the 1980s by Motorola in the United States and focused on reducing variation and improving quality through statistical analysis. By applying advanced statistical techniques, businesses could measure and enhance their performance based on actual data rather than assumptions.

The combination of these two methodologies resulted in Lean Six Sigma, a holistic approach to process optimization that promotes both speed and accuracy.

Lean Six Sigma is centered around customer focus, ensuring that processes are designed to deliver maximum value. Decision-making is driven by data analysis, enabling organisations to measure and enhance their performance based on factual information.

A fundamental aspect of Lean Six Sigma is process optimization, where businesses are encouraged to eliminate unnecessary steps and reduce bottlenecks. Continuous improvement is integral, urging companies to seek ways to make their operations more effective.

The success of Lean Six Sigma also depends on engaged employees and collaboration between different departments. By involving all employees and training them in Lean Six Sigma principles, an organisation can achieve sustainable improvements and reinforce its corporate culture.

Lean Six Sigma follows the structured DMAIC cycle:

Define the problem from a company perspective, stakeholder perspective, and customer perspective. Figure out the quality expectations that customers have and the extent of the problem.

Examine the current process and how it contributes to the problem. Determine whether the process can meet customers' previously defined quality expectations. Match each process step to your quality criteria. Support your measurements with actual performance data.

Examine all information gathered thus far to finalise the exact nature of the problem, its scope, and its cause.

Solve the problem and verify the improvement. Collaborate to structure a solution that eliminates both the problem and its cause. Use your data to ensure that the solution fits the issue at hand. Test the solution and derive performance data to support it.

Monitor improvement and continue to improve where possible. Finalise acceptable performance criteria. Establish a plan that can deal with variations that occur, sustain improvements, and prevent a re-occurrence of the original problem.

Lean and Six Sigma combine to help eliminate eight forms of waste, removing anything from a process – whether its material, time, or effort – that doesn’t add value. The forms of waste – represented by the ‘DOWNTIME’ acronym – are:

• Defects: Products that don’t meet quality standards
• Overproduction: Exceeding demand or producing more than was ordered
• Waiting: Process bottle-necks and downtime
• Non-Utilised Talent: Ineffectively using or misallocating human resources
• Transportation: Inefficient shipping methods
• Inventory: Holding on to a surplus of product or raw material
• Motion: Unnecessary moving of product, material, or people
• Extra Processing: Doing more work than is needed

Lean Six Sigma is widely applied across different industries.

In manufacturing, it helps enhance quality by reducing defects and shortening lead times.

In healthcare, it optimises patient care and reduces wait times by making processes more efficient.

In the financial sector, it results in streamlined workflows and improved risk management.

While in logistics, it enables smarter distribution and inventory management.

Each of these industries benefits from a systematic approach that minimises waste and optimises performance.

A Lean Six Sigma project is completed using five clearly defined steps: define, measure, analyze, improve, and control. These steps constitute the cycle Lean Six Sigma practitioners use to manage problem-solving projects. The steps help practitioners ensure that data-driven decisions are made, root causes are identified, improvements are vetted, and controls are implemented within the process.

At the managerial level, Six Sigma relies on an improvement process that is used by all employees to improve product, service, and process quality. The following is a brief description of each step in the Six Sigma improvement process:

• Define products and services. Describe the products and support services, including information, consulting, and follow up, that are provided to external and internal customers.
• Identify customer requirements. Identify internal and external customers, and determine their requirements for each product or service. These requirements should be stated in measurable terms.
• Compare the product with customer requirements. Identify gaps between what the customer expects and what he or she is receiving. This step also should provide some basis for prioritizing needed improvements.
• Describe the process. Provide a detailed description of each process. Flowcharts and other improvement tools often are used in this step.
• Improve the process. Evaluate each process in terms of its value and relationship to other processes. Changing how the process flows can involve simplification, mistake proofing and/or eliminating or combining process steps.
• Measure quality and productivity. Establish baseline values for quality and productivity, and track improvement. This can include benchmarking best-in-class organisations to provide targets for quality and productivity improvement.

One real-world example involves a hospital that applied Lean Six Sigma to reduce emergency patient wait times. Through process analysis and continuous measurement, it was determined that a significant portion of delays stemmed from inefficient use of medical equipment and poor interdepartmental communication. By addressing these issues, the hospital not only reduced wait times but also improved patient satisfaction.

The techniques and tools used to accomplish essential goals of the Lean Six Sigma strategy include:

This involves workflow management practices, such as work visualisation and limited work in progress, which maximise efficiency and promote continuous improvement.

This is a Japanese word that denotes change for the better or continuous improvement. Practices that engage employees and promote a work environment that emphasizes self-development and ongoing improvement are its focus.

This technique analyzes places to eliminate waste and optimise process steps.

This technique ensures an efficient, productive, safe, and successful workplace.

For professionals looking to expand their knowledge and skills, various Lean Six Sigma certification levels are available. Lean Six Sigma training uses belts to denote Lean Six Sigma expertise. The exact specifications for each belt may differ depending on what organisation provides the certification.

Understands the meaning and goals of Lean Six Sigma and knows the terms associated with the methodology.

Understands essential Lean Six Sigma concepts, tools, and techniques; can be part of project teams and receive JIT (just-in-time) training.

The Green Belt has some expertise in Lean Six Sigma strategy; can launch and manage Lean Six Sigma projects and provide JIT training to others; focuses on the use of tools and the application of DMAIC and lean principles.

Advanced Lean Six Sigma expertise; can be full-time, cross-functional project team leaders as well as coaches/mentors to Green Belts; responsible for putting Lean Six Sigma changes into place.

Has extensive Lean Six Sigma expertise; typically responsible for the Lean Six Sigma initiative; can act as coach or mentor and monitor projects; works with company leaders to identify efficiency gaps and training needs.

Implementing Lean Six Sigma has a direct impact on business performance. Cost savings are achieved by reducing defects and inefficient processes, while improved quality leads to higher customer satisfaction. Lead times are shortened as businesses gain better insight into their workflows and eliminate unnecessary steps. This contributes to increased competitiveness and ensures that businesses can adapt flexibly to market changes. Furthermore, it enhances employee engagement by allowing them to participate in improvement initiatives and feel valued for their contributions.

Another example is a major manufacturing company that used Lean Six Sigma to reduce the defect rate of one of its main production lines. By conducting detailed data analysis, the company identified the primary sources of errors and implemented targeted improvements. Within six months of implementation, defect rates had dropped by 35%, leading to cost savings worth millions of dollars.

While Lean Six Sigma offers many benefits, its implementation also presents challenges. Companies may encounter resistance from employees accustomed to existing workflows and reluctant to change. A lack of proper training and guidance can result in projects failing to achieve the desired outcomes. Additionally, gathering and analyzing the right data to implement improvements effectively can be complex. To overcome these obstacles, it is crucial to foster a culture of continuous improvement and provide adequate education and support. Leadership plays a vital role in the success of Lean Six Sigma, as willingness to change must be supported from the top down.

With the rise of digital technologies, Lean Six Sigma continues to evolve. Automation and artificial intelligence allow for further process optimisation and elevate data analysis to a higher level. Organisations can respond more quickly to changing customer needs by utilising advanced algorithms and real-time monitoring. This means that Lean Six Sigma remains an essential strategy for businesses looking to innovate and remain competitive in an ever-changing market. Moreover, the integration of machine learning and advanced data analytics is expected to make the methodology even more effective.