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DMAIC (Define, Measure, Analyse, 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 describe the problem more effectively.

Now you can Analyse the situation by using facts and data to determine the root cause(s) of the problem that’s inhibiting your performance. With the root cause identified, you can now move to the Improve phase, identifying potential solutions, selecting the most suitable, and testing or piloting it to validate your approach, using data where appropriate. You’re then ready to implement the solution in the Control phase.

The Control phase is especially important. You need to implement your solution, checking that your customers feel the difference in your performance. You’ll need to use data to determine the extent of the improvement and to help you hold the gains. After all your hard work, you don’t want the problem you’ve solved to recur. With the right ongoing measures in place, you should also be able to prompt new opportunities (see Chapter 8 for more on getting the right balance of measures).

The following sections provide a little more detail about the five DMAIC phases. Figure 2-1 shows how the phases link together, though the process is not necessarily linear. It could be that in the Define phase, for example, the problem that you are planning to tackle can’t be adequately quantified. In the Measure phase, you’ll be collecting data that enables you to go back to Define and update your description of the problem.

© John Morgan and Martin Brenig-Jones

Figure 2-1: The five phases of DMAIC.

Defining your project

When you start an improvement project, ensuring that you and your team understand why you’re undertaking the project and what you want to achieve is an essential ingredient for success. With a DMAIC project, you start with a problem that needs to be solved. Before you can solve the problem, you need to define it – not always as straightforward a process as you may think. One of the key outputs from the Define phase is a completed improvement charter.

The improvement charter is an agreed document defining the purpose and goals for an improvement team. It can help address some of the elements that typically go wrong in projects by providing a helpful framework to gain commitment and understanding from the team. Keep your charter simple and try to contain the document to one or two sides of A4 in line with the example shown in Figure 2-2.

© John Morgan and Martin Brenig-Jones

Figure 2-2: A sample improvement charter.

The improvement charter contains the following key elements:

✔ A high-level business case providing an explanation of why undertaking the project is important.

✔ A problem statement defining the issue to be resolved.

✔ A goal statement describing the objective of the project.

✔ The project scope defining the parameters and identifying any constraints.

✔ The CTQs specifying the problem from the customer’s perspective. Unless you already have the CTQs, these may not be known until the Measure phase.

✔ Roles identifying the people involved in and around the project, expectations of them and their responsibilities. The improvement charter forms a contract between the members of the improvement team, and the champion or sponsor.

✔ Milestones summarising the key steps and provisional dates for achieving the goal.

The improvement charter needs to be seen as a ‘living document’ and be updated throughout the various DMAIC phases, especially as your understanding of the problem you’re tackling becomes clearer.

Depending on the nature of your project, you may also need to use some other tools, such as affinity and interrelationship diagrams, which we describe in a moment (see Figures 2-3 and 2-4). If your project is large and potentially complex, an affinity diagram prepares you for success. It can also aid you in developing your improvement charter. Affinity and interrelationship diagrams provide definition for your project and help the team really understand what’s involved. These tools should be used together. The affinity diagram can be the first step in a large project (we like to think of it as ‘step zero’) and it helps the team develop their thoughts on the issues involved. By the time they’ve created the interrelationship diagram, the team will have a detailed understanding of what they need to do, the drivers of success and the many and varied interrelationships involved, and they will feel they own the output from the exercise.

© John Morgan and Martin Brenig-Jones

Figure 2-3: Creating an affinity diagram.

© John Morgan and Martin Brenig-Jones

Figure 2-4: A sample interrelationship diagram.

It’s highly likely that affinity and interrelationship diagrams will be used at the beginning of a design project, where the DMADV method would be used rather than DMAIC.

Figure 2-3 shows the steps in the creation of an affinity diagram. The process works best if you use sticky notes and silently brainstorm ideas on an agreed issue statement; for example, ‘what issues are involved in introducing Lean Six Sigma into our organisation?’

Follow these rules:

✔ Use one idea per sticky note.

✔ Write statements rather than questions.

✔ Write clearly.

✔ Don’t write in upper case (reading lower-case words is easier).

✔ Avoid one-word statements (your colleagues won’t know what you mean).

✔ Include a noun and verb in each statement.

✔ Don’t write an essay.

After everyone has finished writing their sticky notes, maintain the silence and place them on the wall, as shown in the first part of Figure 2-3. Move the notes into appropriate themes or clusters (see the middle figure), you’ll probably need to break the silence here. Finally, give each theme or cluster a title describing its content (see the final figure). Ensure that each title provides enough description; doing so is helpful for when you move into the interrelationship diagram, shown in Figure 2-4.

An interrelationship diagram identifies the key causal factors or drivers for your programme or project, by enabling you to understand the relationships between the themes or clusters. In looking at the different pairs of clusters you’re trying to see if a cause and effect type of relationship exists, so does ‘this’ have to be done before ‘that’, or does ‘this’ drive ‘that’.

In Figure 2-4, the headers for the themes or clusters from the affinity diagram have been put into a clock face on a flip chart and you now work your way round looking at the relationship between each pair. As you do so, you need to consider whether a relationship exists or not, and, where it does, determine which has a greater effect on the other – for example, ‘must this happen before this does?’

If a relationship does exist between two clusters, connect them with a line. Importantly, either there is a relationship or there isn’t, so don’t use dotted lines – you might start with a pencil, though! Agreeing some ground rules is sensible to ensure the relationships are tangible.

After you’ve determined the ‘causal’ cluster, draw an arrow into the ‘effect’ cluster. Some discussion is likely to take place about which way the arrow faces, but it has to go one way or the other – two-headed arrows are not allowed! In Figure 2-4, you can see that A drives B, but that B is the driver of C. The numbers represent arrows out over arrows in.

The finished diagram can be presented as shown in Figure 2-5, and you can clearly see the key driver is A, whereas E is probably the outcome of the project. You need to particularly focus on A to ensure your project or programme is successful.

© John Morgan and Martin Brenig-Jones

Figure 2-5: Identifying the key drivers.

Throughout your project, developing a storyboard summary of the key decisions and outputs helps you review progress and share what you’ve learnt. A storyboard builds up as you work your way through your project by capturing the key outputs and findings from the DMAIC phases. A storyboard would include, for example, your improvement charter and process map (see Chapter 5). The storyboard also helps your communication activities. Developing and reviewing a communication plan is an essential activity. You really need to keep your team and the people affected by your project informed about the progress you’re making in solving the problem you’re tackling. Communication begins on day one of your project.

Measuring how the work is done

After you’ve defined the problem, at least based on your current understanding, you need to clarify how, and how well, the work gets done. To understand the current situation of your process, knowing what it looks like and how it’s performing is important. You need to know what’s meant to happen, and why. Understanding how your process links to your customer and his CTQs is also helpful. What does the bigger picture of the process look like?

Knowing the current performance of your process is essential – this knowledge becomes your baseline – but knowing what’s happened in the past is also useful. Measure what’s important to the customer, and remember also to measure what the customer sees. Gathering this information can help focus your improvement efforts and prevent you going off in the wrong direction. Using control charts (see Chapter 7) can help you make better sense of the data, as they provide a visual picture that demonstrates performance and shows you the variation within the process. Importantly, control charts help you know when to take action and when not to by enabling you to identify the key signals so often hidden when data is presented as a page of numbers.

Lean Six Sigma projects can take longer than you might like because the right data isn’t in place in the day-to-day operation. So often organisations have data coming out of their ears – but not the right data. You need to develop the right measures and start collecting the data you do need – which takes time.

Use the CTQs as the basis for getting the right process measures in place. Understanding how well you meet the CTQs is an essential piece of management information. Chapter 8 provides more detail on getting the right measures.

Analysing your process

In the Measure phase, you discovered what’s really happening in your process. Now you need to identify why it’s happening, and determine the root cause. You need to manage by fact, though, so you must verify and validate your ideas about possible suspects. Jumping to conclusions is all too easy.

Carrying out the Analyse phase properly helps you in determining the solution when you get to the Improve phase. Clearly, the extent of analysis required varies depending on the scope and nature of the problem you’re tackling, and, indeed, what your Measure activities have identified. Essentially, though, you’re analysing the process and the data.

Checking the possible causes of your problem using concrete data to verify your ideas is crucial. In checking the vital few, you may find the ‘usual suspects’ aren’t guilty at all! Identifying and removing the root causes of a problem prevents it happening again.

Improving your process

Most people want to start at this point. Now you’ve identified the root cause of the problem, you can begin to generate improvement ideas to help solve it. Improve, however, involves three distinct phases: