The merged approach provides a comprehensive set of principles, and supporting tools and techniques, to enable genuine improvements in both efficiency and effectiveness for organizations.
Considering the Key Principles of Lean Six Sigma
Lean Six Sigma takes the features of Lean and of Six Sigma and integrates them to form a magnificent seven set of principles. The principles of each approach aren’t dissimilar (check out Chapter 1 to read more about the individual components), and the merged set produces no surprises. The seven principles of Lean Six Sigma are described in the following sections.
Focus on the customer
The elements of your service or offering that customers consider most important are known as CTQs (Critical to Quality requirements) in Lean Six Sigma. (See Chapter 4 for more on CTQs.) Written in a way that ensures they’re measurable, the CTQs provide the basis for determining the measures you need to help you understand how well you perform against these critical requirements. As you improve your performance in meeting the CTQs, you’re also likely to win and retain further business and increase your market share.
Identify and understand how the work gets done
The value stream describes all of the steps in your process — for example, from receipt of a customer order to the issue of a product or the delivery of a service, through to payment. By drawing a map of the value stream, you can highlight the non-value-added steps and areas of waste and ensure the process focuses on meeting the CTQs and adding value. To undertake this process properly, you must “go to the Gemba.” The Japanese word Gemba means the place where the work gets done — where the action is — which is where management begins. You could try Process Stapling (outlined in Chapter 5), which involves spending time in the workplace to see how the work really gets done, not how you think it gets done. This helps you to understand the problems that you want to tackle and determine a more effective solution for your day-to-day activities.
Manage, improve and smooth the process flow
Among the things to look out for when carrying out a Process Stapling exercise (or going to the Gemba) are clues that highlight bottlenecks or interruptions to the flow of work through the process. Are there delays at certain points? Are there high levels of work in progress? We’ll look more closely into bottlenecks in Chapter 11.
Processing work in batches doesn’t help items flow smoothly through the process. If possible, use single piece flow (processing one item at a time), moving away from batches, or at least reducing batch size. The concept of pull, not push (see Chapter 1), links to your understanding the process and improving flow. And it can be an essential element in avoiding bottlenecks. Overproduction or pushing things through too early is a waste.
Remove non-value-adding steps and waste
Focusing on the customer and the concept of value-add is important because typically, still only 10 to 15 percent of the cycle time (or lead time) of a process is spent on value-adding activities. This may be surprising but should grab your attention and help you realize the potential waste at play in your own organization. The concept of value-added process steps is covered in Chapter 10, along with information on the eight types of waste to be on the lookout for.
Manage by fact and reduce variation
Managing by fact, using accurate data, helps you avoid jumping to conclusions and solutions. You need the facts! And that means measuring the right things in the right way. Data collection is a process and needs to be managed accordingly. In Chapter 1, we looked at the significance of variation. Quality guru W. Edwards Deming stated that “uncontrolled variation is the enemy of quality.” In other words, it’s in everyone’s best interest to achieve a consistent, reliable, and predictable level of performance. This can be achieved by understanding and addressing the amount of variation, the type of variation, and the sources of variation. Using control charts (Chapter 8 has more on these) enables you to interpret the data correctly and understand the process variation. You then know when to take action and when not to.
Involve and equip the people in the process
To be effective, you need to involve the people in the process, equipping and empowering them to both feel able and be able to challenge and improve the way the work gets done. Involving people is what has to be done if organizations are to be truly effective, but, like so many of the Lean Six Sigma principles, it requires different thinking if it’s to happen. (See Chapter 6 for more about the power of the people.) Continuous Improvement is a mindset — some call it a “growth mindset” — that embraces challenges and seeks opportunities to learn and understands that it’s worth putting in the effort to get the results. Leaders play an important role in creating this type of spirit in their organizations so that everyone can contribute.
Undertake improvement activity in a systematic way
The systematic approach used is known as DMAIC: Define, Measure, Analyze, Improve and Control. One of the criticisms sometimes aimed at “stand-alone” Lean is that improvement action tends not to be taken in a systematic and standard way. In Six Sigma, DMAIC is used to improve existing processes, but the framework is equally applicable to Lean and, of course, Lean Six Sigma. Where a new process needs to be designed, the DMADV method is used. Chapters 14 and 15 describe DMADV and the Design Thinking approach.
The focus in the following section is on improving existing processes with DMAIC using the appropriate tools and techniques from the Lean Six Sigma toolkit. But these tools, and the seven principles identified earlier in this chapter, also provide a framework to improve the day-to-day management and operation of processes. We look at this aspect of Lean Six Sigma, which we refer to as “Everyday Operational Excellence,” in Chapter 18.
Improving Existing Processes: Introducing DMAIC
DMAIC (Define, Measure, Analyze, Improve, and Control) provides the framework to improve existing processes in a systematic way. DMAIC projects begin with the identification of a problem, and in the Define phase you describe what you think needs improving. Without data this might be based on your best guess of things, so in the Measure phase you use facts and data to understand how your processes work and perform so that you can pinpoint the problem more effectively.
