Lean Six Sigma

What is Lean?

Lean methodology has been labelled a process improvement toolkit, a philosophy, and a mindset. It originated in the 1940s. At its core, Lean is a popular approach to streamlining both manufacturing and transactional processes by eliminating waste and optimizing flow while continuing to deliver value to customers.

What is Six Sigma?

Six Sigma is a process improvement strategy that improves Output quality by reducing Defects. It originated in the 1980s. Six Sigma is named after a statistical concept where a process only produces 3.4 defects per million opportunities (DPMO). Six Sigma can therefore be also thought of as a goal, where processes not only encounter less defects, but do so consistently (low variability). It is a data-driven approach that uses a statistical methodology for eliminating defects.

The etymology is based on the Greek symbol "sigma" or "σ," a statistical term for measuring process deviation from the process mean or target. "Six Sigma" comes from the bell curve used in statistics, where one Sigma symbolizes a single standard deviation from the mean.

If the process has six Sigma, three above and three below the mean, the defect rate is classified as "extremely low."

Combining Lean and Six Sigma into Lean Six Sigma

Although Lean and Six Sigma have been taught as separate methods for many years, the line has blurred and it's now common to see Lean and Six Sigma teachings combined as Lean Six Sigma to reap the best of both worlds.

Lean Six Sigma provides a systematic approach and a combined toolkit to help employees build their problem-solving muscles. Both Lean and Six Sigma are based on the Scientific Method and together they support organizations looking to build a problem-solving culture. This means that "finding a better way" becomes a daily habit.

Understanding both approaches and accompanying toolkits is extremely valuable when solving problems. It doesn't matter where a tool comes from—Lean or Six Sigma—if it does the job. By combining these methods, you have the best shot at applying the right mindset, tactics, and tools to solve the problem.

LEAN Management

You have probably heard of the Lean management concept and its growing popularity in the business world.Lean management is a business methodology that's designed to increase quality and efficiency by eliminating wasted resources like time, money, and effort. It also is sometimes referred to as lean production or lean manufacturing. The idea is to produce only the best and most valuable services or products for customers and clients at the right price.

The Lean methodology relies on 3 very simple ideas:

• 1. Deliver value from your customer's perspective
• 2. Eliminate waste (things that don't bring value to the product)
• 3. Continuous improvement

Using the Lean methodology, you can remove the below mentioned eight types of waste ("DOWNTIME" is the acronym for the eight wastes).

Waste	Definition of waste
Defects	The efforts involved inspecting for and fixing errors, mistakes through reworks.
Overproduction	Producing more products or services that the customer needs or downstream process can use.
Waiting	Idle time created when material, information, people, or equipment is not ready. It includes high job set up time in manufacturing. Or excessively high data processing time in the service industry.
Non – Utilized Talent	Not adequately leveraging peoples' skills and creativity. Employee empowerment can counter this waste as advocated by Japanese quality pioneers.
Transportation	Moving products, equipment, material, information, or people from one place to another, without any value addition to the final product or service.
Inventory	Unnecessary/ Unwanted stocking or storage of information and/ or material (eg WIP, WIQ – work in the queue)
Motion	Unnecessary movement of people or machines that takes time and uses energy. It may cause fatigue to workmen due to unwanted movement of a body.
Extra Processing	Process steps that do not add value to the product or service, including doing work beyond a customer's specification.

Principles of Lean Six Sigma

Lean management revolves around these core principles: defining value, mapping stream value, creating flow, establishing pull, and pursuing perfection.

Defining Value

This principle identifies the value of a product or service from the customer's perspective. Rotating Solutions highlights the importance of creating and focusing on a timeline for the production process, including delivery. This can include detailing crucial requirements, price points, expectations, and other essential information

Mapping Stream Value

This principle is also known as waste mapping. It examines all steps of any given business process to determine which unnecessary actions and resources can be eliminated to maximize efficiency

Creating Flow

This principle focuses on attaining efficiency and speed, as well as ensuring that multiple operational tasks are completed as quickly and smoothly as possible without sacrificing quality

Establishing Pull

Create a flow in which there are just enough materials and resources to create the required products on time and in a continuous fashion.

Pursuing Perfection

Really, this means making sure that the other four principles occur continuously and consistently. Make sure all employees are also on board with the ultimate lean mission.

The Six Sigma Methodology

The two main Six Sigma methodologies are DMAIC and DMADV. Each has its own set of recommended procedures to be implemented for business transformation.

• DMAIC is a data-driven method used to improve existing products or services for better customer satisfaction. It is the acronym for the five phases: D – Define, M – Measure, A – Analyse, I – Improve, C – Control. DMAIC is applied in the manufacturing of a product or delivery of a service.
• DMADV is a part of the Design for Six Sigma (DFSS) process used to design or re-design different processes of product manufacturing or service delivery. The five phases of DMADV are: D – Define, M – Measure, A – Analyse, D – Design, V – Validate. DMADV is employed when existing processes do not meet customer conditions, even after optimization, or when it is required to develop new methods. It is executed by Six Sigma Green Belts and Six Sigma Black Belts and under the supervision of Six Sigma Master Black Belts.

Six Sigma Techniques

The Six Sigma methodology also uses a mix of statistical and data analysis tools such as process mapping and design and proven qualitative and quantitative techniques, to achieve the desired outcome.

Brainstorming

Brainstorming is the key process of any problem-solving method and is often utilized in the "improve" phase of the DMAIC methodology. It is a necessary process before anyone starts using any tools. Brainstorming involves bouncing ideas and generating creative ways to approach a problem through intensive freewheeling group discussions. A facilitator, who is typically the lead Black Belt or Green Belt, moderates the open session among a group of participants.

Root Cause Analysis/The 5 Whys

This technique helps to get to the root cause of the problems under consideration and is used in the "analyze" phase of the DMAIC cycle.

In the 5 Whys technique, the question "why" is asked, again and again, finally leading up to the core issue. Although "five" is a rule of thumb, the actual number of questions can be greater or fewer, whatever it takes to gain clarity.

Voice of the Customer

This is the process used to capture the "voice of the customer" or customer feedback by either internal or external means. The technique is aimed at giving the customer the best products and services. It captures the changing needs of the customer through direct and indirect methods. The voice of the customer technique is used in the "define' phase of the DMAIC method, usually to further define the problem to be addressed.

The 5S System

This technique has its roots in the Japanese principle of workplace energies. The 5S System is aimed at removing waste and eliminating bottlenecks from inefficient tools, equipment, or resources in the workplace.

The Five 'S' are,

• 1. Seiri (organize): eliminating clutter from the workspace
• 2. Seiton (orderliness): ensure order by following "a place for everything and everything in its place"
• 3. Seiso (cleanliness): clean the workspace and keep it that way
• 4. Seiketsu (standardize): standardize all work processes, making them consistent
• 5. Shitsuke (sustain): constantly reinforcing the first four steps

Kaizen (Continuous Improvement)

The Kaizen technique is a powerful strategy that powers a continuous engine for business improvement. It is the practice continuously monitoring, identifying, and executing improvements. This is a particularly useful practice for the manufacturing sector. Collective and ongoing improvements ensure a reduction in waste, as well as immediate change whenever the smallest inefficiency is observed.

Refer KAIZEN section below for more details

Benchmarking

Benchmarking is the technique that employs a set standard of measurement. It involves making comparisons with other businesses to gain an independent appraisal of the given situation. Benchmarking may involve comparing important processes or departments within a business (internal benchmarking), comparing similar work areas or functions with industry leaders (functional benchmarking), or comparing similar products and services with that of competitors (competitive benchmarking).

Poka-yoke (Mistake Proofing)

This technique's name comes from the Japanese phrase meaning "to avoid errors," and entails preventing the chance of mistakes from occurring. In the poka-yoke technique, employees spot and remove inefficiencies and human errors during the manufacturing process.

Value Stream Mapping

The value stream mapping technique charts the current flow of materials and information to design a future project. The objective is to remove waste and inefficiencies in the value stream and create leaner operations. It identifies seven different types of waste and three types of waste removal operations.

Some Important Lean Tools

• VSM (Value Stream Mapping): As already discussed, VSM helps to identify process wastes and causes of these wastes.
• Kaizen: It's a continuous improvement approach focusing on small – small improvements. It involves the commitment of down-level people in the organization towards process improvements, facilitated by subordinates and supported by management.
• Just in Time: It's a pull approach to meet customer demands as & when it flows from a customer.
• SMED (Single minute exchange of dies): It improves equipment changeover time. It works on the principle of reducing changeover time to within ten minutes.
• Poke Yoke: It's a mistake-proofing device used in assembly to alert operators on defects or failures.
• Jidoka (Autonomation): Also known as intelligent automation. It stops the assembly or production line if a defect occurs.
• Heijunka: It's the concept of Line Balancing. The aim is to evenly distribute the load by balancing production lines.
• Gemba (Go & See): The aim is to go to the actual place of work. Observe the process and executions in real-time with care. Record the observations. It's another way to find process pitfalls.
• Kanban: It's a signal system to manage inventory levels. Kanban boards can be displayed and managed to see the current inventory level on a real-time basis. It also alerts the management to bring attention to excessive inventory. Excessive inventory ties up the working capital and blocks it from productive usage.

Other LEAN Six Sigma Tools

Many elements within the concept of lean production stand out and each of these presents a particular method:

• Elimination of Time Batching or Just in Time (JIT)
• Total Productive Maintenance
• Mixed Model Processing
• Single Point Scheduling
• Rank Order Clustering
• Multi-process Handling
• Redesigning Working Cells
• Control Charts for Statistical Process Control (for checking mura) also known as Statistical Quality Control (SQC)