Everything You Need to Know About Lean Six Sigma

Common wisdom holds that you start with Lean to streamline and reduce waste, and then fine-tune the process by adding in Six Sigma. 
 
The 5 S’s

Source: Teian Consulting International, Singapore.
 
You can start promoting Lean culture through a practice such as the 5S’s. In Japanese, the S’s stand for Seiri, Seiton, Seiso, Seiketsu, and Shitsuke. In English, the S’s roughly translate to: 

• Sort: Clear the workplace of unnecessary items (things that take up space, present hazards, or clutter).
• Set in Order: Organize the work area so you can easily find, use, and replace things. This concept applies to your desk as well as to the production floor.
• Shine: Like your mother always told you, keep things neat, tidy, and clean.
• Standardize: Make tasks and procedures repeatable. Find the most efficient way to do things and always do it that way.
• Sustain or Self Discipline: Turn the good practices into habits. 

  
Beware the 7 Wastes 
The 7 muda (or 7 wastes) were articulated by Taiichi Ohno at Toyota. Waste is defined as anything that doesn’t add value, including actual waste and inefficiencies. The 7 Wastes are what the Lean practice of Lean Six Sigma seeks to avoid. Various mnemonics exist to help you remember the seven wastes. Here we use TIMWOOD:

• Transportation: Moving material or product doesn’t actually add value, but the customer pays for it.
• Inventory: Until the product is sold, it is inventory, and therefore of no direct value. Raw material or an unfinished piece is also inventory. These products may need to be transported, or stored in a warehouse that must be heated or refrigerated, and secured. It is a loss if the inventory is stolen, so it’s imperative to reduce sitting inventory whenever possible.
• Motion: When tools at a workbench or in a kitchen are not organized well, motion is wasted through inefficient movements. Excessive or indirect movement of supplies to work benches and of finished items to a storeroom also wastes motion.
• Waiting: Waiting (for materials from a supplier, for answers to questions from management, etc.) wastes time, and therefore, money.
• Over Processing: This occurs when using the wrong processes or machines for a deliverable. Generally, over processing refers to using equipment much more elaborate than the job warrants. Examples of over processing include launching a CMS to fix an HTML error that would take five seconds to fix in text format, or warming an electric oven for a single-portion casserole. 
• Overproduction: Considered the worst waste of all, overproduction is making too much or producing while there is still inventory on hand. Overproduction calls for implementing Just in Time (JIT). You can prevent some timing issues through Takt time, a Lean formula which calculates the rate at which a product must be finished to satisfy customer demand. 
• Defects: If caught early, defects result in rework. However, if a defect is caught late in the production cycle - at worst, by a customer - it can result in returns and refunds. One of the Lean tools used to avoid defects is poka yoke.

Lean Six Sigma Analysis Tools
Lean Six Sigma borrows many tools from Lean management. The following are some of the key devices for creating happy and efficient business. 
 

• Kaizen: Most well-known, Kaizen is broadly interpreted as the philosophy of continuous improvement. The ultimate goal may be higher quality products and more money, but achieving that goal is accomplished through empowering everyone throughout an organization, from CEO to janitor. Every employee is taught to recognize waste and how to use analytical methods to find solutions. Kaizen events are improvement efforts that involve a small team who spends a short time (usually about a week) brainstorming solutions and improvements, which they then present to the rest of the company. The solutions are periodically reviewed to ensure that they continue to benefit the team. As part of continual improvement, Kaizen events should be regular events. 
• Value Stream Mapping:  Like a process flow, creating a value stream map helps to record and analyze the flow of materials or information used to create a product. Sometimes a value stream map is used with 5 Whys questioning to help filter the flow to its essential steps. 

• 5 Whys: An iterative information gathering process that groups use to discover root causes. First, ask why a problem is occurring, then verify that the answer is fact and not belief, and then continue to ask why to each successive answer.
• Ishikawa Diagram: Developed by Professor Kaoru Ishikawa, it is also called a Fishbone diagram or a CE diagram for cause and effect. An Ishikawa diagram is used in group discussions to visualize all the different contributing factors in a problem. Part of the diagram’s benefit is to depersonalize the issue. 

• Poka Yoke:The concept of mistake proofing involves designing a process that eliminates room for mistakes. This word comes from the Japanese pokeru (to avoid), and yoke (mistakes). Anyone throughout a company can implement poka yoke. In manufacturing, it might mean presenting all pieces at once so that the assembler can check that everything is present. In a transactional environment, it might mean presenting a checklist for verifying all necessary paperwork. 
• Visual Workplace: Closely associated with the 5S’s, a visual workplace was developed from visual thinking, which leverages the power of graphics and pictures to increase safety and efficiency. One essential tenet is that important information should be located as close to the object of the information as possible. Using a visual workspace is a useful tool for factories, healthcare facilities, airports, and any place where safety is paramount. 

Gwendolyn Galsworth formalized the notion of the visual workplace in the book Visual Workplace, Visual Thinking. She wrote: 

"The visual workplace is a self-ordering, self-explaining, self-regulating, and self-improving work environment—where what is supposed to happen does happen, on time, every time, day or night—because of visual devices.”  

• Heijunka: A load balancing japanese word for leveling. Employ this tool after using Kaizen and value stream mapping to fine-tune inventory and scheduling by balancing the load of production based on orders. For example, a jewelry manufacturer may receive 100 orders for an engagement ring every month, but the number of orders may vary by week. The jeweler may then decide to create 25 rings every week. That way, craftspeople are neither rushed nor left without work. A heijunka box is a tool used to organize and display the work load. It is often a wallboard with pockets that contains colored cards, known as Kanban cards.

 
When It’s Time for Six Sigma
If defects and problems persist, it’s time for Six Sigma. Six Sigma can involve sophisticated statistical tools, but the method, or roadmaps, provide a consistent path for determining problems, causes, and solutions. For existing processes and products, use the DMAIC method: 
 

• Define the problem. Examples of problems include customer complaints, invoicing problems, responsiveness problems, too much inventory, returns and defective products. 
• Measure the quantifiables around the process and problem.
• Analyze the cause through findings.
• Improve or implement a solution.
• Control the process to maintain continued success.

For new processes and products, certain methods attempt to preempt defects. The old name for this process is DMADV, or Design, Measure, Analyze, Design (incorporating comments), and Verify. Today the process if often referred to as DFSS, which stands for Design for Six Sigma. DFSS includes four phases, IDOV:
Identify the customer and requirements.

• Design the product, with an emphasis on what’s critical to quality (CTQ).
• Optimize the design by using statistical methods to predict its effectiveness.
• Verify that the implemented design works and meets requirements.