Can Scrum Support Six Sigma?
By Heitor Roriz Filho, MSc, CSP
Certified Scrum Trainer and Agile Coach
Rally Software partner for Latin America
This article discusses briefly how Scrum could support Six Sigma projects. Issues of whether Six Sigma is used specifically in software or other product development are not considered. If you ask yourself "Why should Scrum support Six Sigma projects?" I can promptly reply, "Why not?"
Moreover, the question of how Scrum, a lightweight framework for project management and other predictive and detailed methodology have led to process improvement has already been addressed in    .
SIX SIGMA ASPECTS OVERVIEW
Six Sigma can be considered a detailed and structured methodology to execute projects in a company. To ensure the success of Six Sigma methodology implementation, some critical factors must be verified. A study by McAdam and Lafferty reveals the necessity of employer's empowerment applied with the right tools and methods, in order to achieve the Six Sigma proposed goals in an autonomous and responsible way .
Six Sigma as a new paradigm of excellence can result in a huge amount of investment, and it can be questioned if there are other methods that require fewer resources and achieve similar results. Six Sigma still has a long road ahead until it can be accepted as a change philosophy applied to companies in general .
In parallel to this movement, another methodology called Lean Manufacturing or Lean Production was developed, and the union of these two process improvement methodologies is called Lean Six Sigma. Originally focused on improvement with a special attention to losses reduction, the concept became one of the most important points of Taiichi Ohno's philosophy, the mentor of the Toyota Production System (TPS). Combining JIT, KANBAN, Quality Circles and CEP, he focused on saving Toyota from a big crisis during the 50´s, which they not only overcame but also won the Japanese Quality Award, the Deming Prize.
Nowadays, many consulting companies look for Six Sigma experts as well as experts in Program and Lean Production, and even though training costs remain above average, many companies are still embracing these programs. On the other hand, some online communities such as TreQna (www.treqna.com) are freely sharing Six Sigma and Lean Production concepts, ensuring many options to people interested on acquiring such knowledge.
The deployment of any program or strategy always depends on people's behavior. In  this behavior is divided into two independent and important groups, the top management and the people in charge of the program implementation. The behavior of these two groups is strongly related to their creeds and values, and significantly contributes to the implementation success of a process improvement program such as Six Sigma.
SIX SIGMA ROLES AND METHOD
Six Sigma is based on a people structure of three main roles, Champions, Black Belts, and Green Belts working in a framework such as DMAIC (Define-Measure-Analyze-Improve-Control), a 5-phase method based on PDCA and focused on problem-solving. The Champions have the responsibility to properly define the project scope (during the Define phase) and support the project during the other phases. The Black Belt has the responsibility to communicate frequently with Champions and team members during the project execution, and act as a project leader. Green Belts act as team members and play an active role in the Measure, Analyze, and Improve phases. Finally, all members work together to ensure the sustainability of improvements during the Control phase.
THE SCRUM ROLES
Scrum is focused on its process, three roles, and some artifacts. The three roles in Scrum are the Product Owner, the ScrumMaster, and the Scrum Team.
The artifacts in Scrum are the Product Backlog, the Sprint Backlog, and the Burndown Graph. The Product Backlog contains a prioritized list of the client's needs, i.e., all activities to be performed in order to get the product done. This list is prioritized according to the client necessities; the more business value, the higher on the list the activity will be placed. The Sprint Backlog is a list of activities broken into tasks that are selected in the beginning of a Sprint (a time-boxed iteration usually ranging from two to four weeks). A Burndown Graph displays the remaining work in a Sprint. The literature about Scrum artifacts is vast. More on the artifacts can be found at   .
The Product Owner (PO) has several responsibilities in a project ranging from defining the product vision to managing the Return on Investment (ROI). The PO represents the needs of the client in a project and is in constant and close contact with the client as well as with the Scrum Team and ScrumMaster. The ScrumMaster is a facilitator in the Scrum process. He is the one responsible for ensuring that Scrum is correctly understood and is correctly followed by the team and PO. The Scrum Team is comprised by those who actually perform the activities necessary to get the product done during the several Sprints.
The Product Owner builds the Product Backlog, a prioritized list of the client's needs. These needs are expressed and/or written in the form of User Stories . Before starting a Sprint, the Scrum Team, the ScrumMaster and the Product Owner perform the planning in a ceremony called the Sprint Planning Meeting. During this meeting the stories with higher priorities are thoroughly discussed and understood by all involved in the process. The Scrum Team then takes these stories and breaks them down into activities, which are the tasks needed to be performed in order to get each story done. These activities comprise the Sprint Backlog.
With the Sprint Backlog the Scrum Team starts to perform in the Sprint. During each day of the Sprint, the Daily Scrum takes place. During this 15-minute standup meeting, each member of the team answers three questions: What did I do yesterday? What I am going to do today? Are there any impediments? It is important to point out that the ScrumMaster acts as a facilitator during the whole process. During the Sprint he will be the one responsible to check whether the Scrum Process is being correctly followed and will protect the team from external interferences, including facilitating the removal of all possible impediments for the tasks.
At the end of the Sprint an increment of the product is delivered. Two ceremonies are performed, the Sprint Review, where the potentially deliverable product increment shall be accepted by the Product Owner, and the Sprint Retrospective, where the team discusses improvements that can be done during the next Sprint. These improvements range from changes in artifacts to better personal interaction.
We can see in this section that Scrum has a very simple yet immutable core process. It is important that this remains unchanged; otherwise we will not be speaking about Scrum, but something else. The next section will talk about how to blend this Scrum kernel into Six Sigma's.
BLENDING SCRUM INTO DMAIC
Scrum is extremely critical regarding the pureness of its architecture while Six Sigma is focused on reaching high quality products performance through variation reduction. The combination of these two concepts can be extremely powerful to bottom-line applications, mainly because Scrum has a strong alignment with lean principles. Furthermore, Six Sigma implementations blended with Lean principles (Lean Six Sigma) can be found in the industry and have become subject to many studies. We believe this diversity ranging from Lean and behavioral aspects and thoughts to predictive and detailed ideas can lead to better performance . As pointed out by , Six Sigma should not focus only on the "how to do" the continuous improvement, evaluating the processes performance and business results, but also verify the people engagement and motivation. Therefore, both concepts can combine and complement each other, improving results.
Focusing on high quality products performance and establishing metrics based on statistics, Six Sigma manages a strong, continuous improvement of the manufacturing process. On the other hand, Scrum is a people-centered approach. Its essence surrounds its process and it has a profound effect on people's behavior: it affects the level of commitment in projects tending to facilitate the adoption of new ideas, i.e., it fights the resistance to change.
I start by grouping Six Sigma in six perspectives as shown in Figure 1 below.
The focus on clients' perspective aims to determine the VOC (Voice of Client) variable. Scrum has a very strong focus on the client. The client has its voice through the role of the Product Owner, which acts as a proxy of the client and communicates to the Scrum Team her vision and goals in the scope of the project. The fourth perspective is strongly based on statistical measurements. While Scrum has no predefined statistics in its core, it does aim to achieve improvement through collaboration and communication, i.e., developing strong and fruitful interactions among people. For these two perspectives it does not matter what process tool is used: DFSS, DMAIC, DMADV, etc.
DMAIC is one of the tools found in the perspective number 3 above. The steps defined by DMAIC is where Scrum can produce more tangible results and establish how both concepts intermingle as this is where project management initiatives in Six Sigma are located.
In order to apply Scrum in a Six Sigma project, we propose the following correlation among the roles of both concepts, shown in Figure 2 below.
One of the common mistakes that organizations make when implementing statistical thinking as in Six Sigma implementations is using measurement for motivational purposes . Scrum as a PM framework can collaborate with Six Sigma leveraging the commitment of the team in both Operational and Managerial levels as depicted in Figure 3 below.
In order to blend Scrum and Six Sigma concepts, we consider that an organization comprises two parts, namely the managerial and operational level. We can then visualize the enterprise in terms of project management, where in the managerial level we find all types of executive work, except project management itself. Project management activities can be found in the operational level.
In the managerial level, Scrum would leverage the premise of any Six Sigma implementation, i.e., the support of senior executives. Applied to this level one can setup business-specific Sprint and Product Backlogs and run their activities according to Scrum's Heart and Soul . This approach has been termed Executive Scrum by Magno .
The operational level is where DMAIC comes into play. Defining, measuring, analyzing, improving, and controlling are done during project execution. Champions (executive board) determine priority of upcoming tasks according the last DMAIC cycle. This prioritization comprises the Sprint Backlog for one Sprint.
CRITICAL ASPECTS TO CONSIDER
Six Sigma's VOC is a critical aspect of the methodology. This is generally not considered as much as it should be in any Six Sigma implementation. Deming's system of profound knowledge has four points :
1. Appreciate the system.
2. Understand variation.
3. Theory of knowledge: PDCA as constant improvement.
4. Psychology. In our case, understand what engages people in their work.
Generally, Six Sigma is seen as being focused mostly on points 2 and 3. The point is that it does not matter how precise or improved a process can be if it does not meet the client's needs. Points 1 and 4 of Deming's system are those that interface with client's needs. This is where Scrum comes into play, as it has a strong focus on this and aims to work in collaboration with clients during every Sprint.
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