Lean and six sigma are two popular methodologies for improving processes, quality, and efficiency in industrial engineering. But how can you compare them and decide which one is more suitable for your project or organization? In this article, we will explore the main differences, similarities, and benefits of lean and six sigma, and give you some tips on how to apply them in practice.
Lean is a philosophy and a set of tools that aim to eliminate waste and increase value for customers. Waste is anything that does not add value to the product or service, such as defects, overproduction, waiting, inventory, transportation, motion, and over-processing. Lean focuses on identifying and removing these sources of waste, and optimizing the flow of value from the beginning to the end of the process. Lean also emphasizes continuous improvement, customer satisfaction, and employee empowerment.
Lean is a mindset, culture, mentality that anyone can use and/or implement at any time. Anyone can be a lean thinker and contribute to continuous improvement.
Lean also aims at reducing variability since one-piece flow cannot be achieved in the presence high variation. When there is variability, on must use a variability buffer : inventory, time (delay or waiting), capacity. Many Lean tools actually result in much lower variability: SMED reduces the setup time but also its variability, 5S often reduces the variability resulting from searching for tools, Poka Yoke reduces the variability in productivity resulting from errors, standatd work reduces the variability in execution, etc.
Six sigma is a methodology and a set of tools that aim to reduce variation and improve quality in processes. Variation is the deviation from the desired or expected outcome, which can lead to defects, errors, rework, and customer dissatisfaction. Six sigma focuses on measuring and analyzing the performance of processes, and finding and eliminating the root causes of variation. Six sigma also follows a structured approach, called DMAIC, which stands for Define, Measure, Analyze, Improve, and Control.
Lean and six sigma have different origins, goals, and perspectives. Lean originated from the Toyota Production System, and its main goal is to eliminate waste and increase value. Lean takes a holistic and systemic view of the process, and looks for ways to improve the flow and efficiency. Six sigma originated from Motorola, and its main goal is to reduce variation and improve quality. Six sigma takes a statistical and analytical view of the process, and looks for ways to improve the accuracy and reliability.
Lean and six sigma have some common elements and principles. Both methodologies aim to improve processes, quality, and efficiency, and to deliver better results for customers and stakeholders. Both methodologies use data and evidence to drive decision making and problem solving. Both methodologies rely on teamwork and collaboration, and require the involvement and commitment of leaders and employees. Both methodologies also seek to create a culture of continuous improvement and learning.
Six Sigma DMAIC can be approximately mapped to PDCA on an A3. Define/Measure/Analyze are all things you might do as part of planning an improvement to a process. Improve and Do are action phases. The Control phase is similar to Check/Act where you work to monitor the improvement to see if it truly works as expected and make small adjustments to ensure the improvement is permanent. In the end, DMAIC is more useful when you have no idea what the solution is. PDCA works well when you already have a good understanding of the problem and potential solution.
Lean and six sigma can offer many benefits for industrial engineers and their organizations, such as reducing costs and waste, improving quality and customer satisfaction, and enhancing productivity and performance. Additionally, applying lean and six sigma can streamline and simplify processes, increase innovation and creativity, and boost morale and motivation. These improvements can lead to increased profits, savings, reduced defects and complaints, shorter cycle time and lead time, the elimination of unnecessary steps and activities, the fostering of new ideas and solutions, as well as the empowerment and engagement of employees.
Lean and Six Sigma plays a major role in every organization, especially if you are an industrial engineer. Lean and Six sigma goes in hand when it comes to reducing variation in a process, elimination of NNVA (Necessary Non-Value Added Activities), streamlining the processes by VSM (Value Stream Mapping) and so on. An Industrial Engineer mindset should look at things that aim to improve the process efficiency to maximum extent that incorporates use of Lean and Six sigma as a part of continuous improvement in their workplace.
Lean and six sigma can be applied to any process, product, or service, regardless of the industry or sector. To ensure successful implementation, it is important to start with a clear vision and purpose that aligns with customer and stakeholder expectations. Then, assess your current state and identify gaps and opportunities for improvement. Select the most appropriate methodology and tools for your project, and follow a systematic and disciplined process. Collect and analyze data to identify the root causes of your problems, then implement and test solutions to monitor their impact. Standardize and sustain the improvements, document best practices, review results, celebrate achievements, learn from the experience, and plan the next steps for improvement.
In my opinion, drawing a comparison is not correct. Both these methodologies have their distinct differences and both cater to achieve different goals from process optimization perspective. I would recommend to intertwine both the methodologies, as found suitable for the given process and reap the benefits. The efficacy of the resulting intertwined process again depends upon the team's process knowledge, team's overall experience and most importantly whether the Customer needs / is interested. Design Thinking can be used to trigger the creativity and to achieve & assess whether the desired optimization objectives are achieved.