Six Sigma Techniques for IT Management

This is the second part of Linh Ho's series on how you can apply Six Sigma techniques in the real world. Six Sigma may be the single most important quality method to be developed in the world of manufacturing. Now it's time to apply it to IT. You can read Part 1 here.

While Six Sigma is a proven quality method in the business world championed by some of the renowned Global and Fortune 500 company leaders, what can it do for IT service management (ITSM)?

In the first article of this series (Part 1), we covered the basics of Six Sigma and its core DMAIC (Define, Measure, Analyze, Improve and Control) model. We also touched on how Six Sigma helps IT baseline service quality levels, quantify improvement for return on investment, and sustain improvement through measurement and reporting.

So, how do we apply it to the ITSM world? Which techniques are useful for ITSM?

In this article, we look at the techniques underpinning the DMAIC and consider which are most relevant for ITSM. More importantly, how Six Sigma brings business focus to ITSM.

How is Six Sigma applied in the real world?

Organizations that have applied Six Sigma fall into two camps-those that use select techniques from Six Sigma to measure, analyze and improve service quality, and those that run full Six Sigma projects (as part of a corporate improvement initiative) using the DMAIC model, including certified Master Black Belts, Black Belts and so on. Both are able to utilize Six Sigma to measure and improve the quality of service where it is most important to the business. Tools such as Minitab, Excel spreadsheets and PowerPoint have been used for analysis and reporting. However, in IT service management, technology vendors already automate the techniques-making it easier for practitioners to apply Six Sigma and immediately gain its benefits. Automating data collection, measurement and reporting makes it much more effective to adopt Six Sigma-whether the company is Six Sigma-committed or not.

Six Sigma techniques for IT service management

A sample list of Six Sigma techniques is below with a short description. To help put it into the DMAIC perspective, most of these are covered in the DMAIC grid (see the table below). These techniques are not ranked in order of importance.

  • Cause and effect (fishbone or Ishikawa) diagram

The fishbone diagram provides an understanding of the causes and effects of the problem. It is often used to brainstorm and find all the factors that influence an outcome. Potential problem areas are being mapped onto this diagram, and the results can be used as input for the Failure Mode and Effects Analysis (FMEA).

  • Control charts

Control charts ensure that a process or service performance is within an acceptable range, bounded by an upper and lower limit. Should performance criteria be abnormal (for example, if a trend line deviates from the mean-known as the centerline-or if it crosses over specified limits), the user can take immediate corrective action. In IT, many practitioners use this technique for ongoing measurement and reporting of critical application response times, business relevant metrics (customer satisfaction metrics), incident volume and/or other business-focused service-level agreements.

  • Correlation diagrams

Correlation diagrams indicate the relationships and dependencies between variables-for example, slow response time of a business application during peak business hours. Correlation charts help IT analyze the data points and their dependencies.

  • Failure Modes and Effects Analysis

FMEA mitigates risks by identifying potential failures and effects of the failures on a process, and prioritizing the problems using a risk rating system. The rating system consists of three components, using a score of 1 to 10 for severity, probability and detectability of failure, to find the total Risk Priority Number (RPN) for the potential problem. The RPN is found by multiplying the three numbers together. This technique can easily be applied for risk management and compliance projects, to help identify and mitigate the risks of non-compliance. Specifically, the RPN helps understand the current IT operational risks and alleviate those that underpin critical business services.

  • Pareto charts

The Pareto chart prioritizes improvement initiatives where the return is the greatest to the business. This is based on the "80/20 rule," first coined by Pareto, the Italian economist: understanding that 20 percent of the causes create 80 percent of the problems. In IT terms, this helps identify the top root causes (e.g., components of the IT infrastructure) that are creating the majority of the problems impacting a critical business service.

  • Process map

Process mapping helps understand the people, processes, technology and their relationships; it displays how the IT service supports the process and what infrastructure is used by the IT service. The process map can also be used to map the Critical to Quality (CTQ) business processes and their underlying IT services and components. This information can then be used to create service models for Business Service Management and Service Level Management initiatives.

The diagram below shows an example of the service model highlighting some of the key business services, based on process map information.

  • Process sigma value

The sigma value is a quality metric that corresponds to the process or service performance. This value represents a key measure of IT service quality delivered to the business.

  • Voice of the Customer

ITIL and Six Sigma strongly advocate capturing the end users'/customers' perception of quality. It is often found that the "perception" of the end users/customers does not always reflect the true quality of service being delivered. It is helpful to capture ideas, opinions and feedback, and also identify CTQ requirements. Voice of the Customer can be executed through surveys over the phone, in person, via e-mails, or in face-to-face meetings and workshops.






  • Identify problem.
  • Define measurable objectives and end results.
  • Benchmark current process performance.
  • Identify root cause of problem.
  • Recommend and implement solutions.
  • Sustain improvement.
  • Predict process behavior.
  • Brainstorm and understand impact of problem.
  • Define process to investigate.
  • Ensure common understanding across the project.
  • Collect data
  • Identify critical to quality measures (CTQs).
  • Baseline these measures and identify process areas that fall outside CTQ upper and lower thresholds.
  • Take data and analyze the process map for improvement opportunities.
  • Determine root cause of problem.
  • Brainstorm solutions to the problem.
  • Produce action plan with owners allocated.
  • Develop new process and pilot it.
  • Measure impact of improvement.
  • Continuously monitor process performance.
  • Take action when thresholds are breached and bring back into control.
  • Voice of the Customer (VOC): surveys, interviews.
  • Affinity Diagram: brainstorming/categorizing ideas.
  • Pareto Charts: identify key bottlenecks and prioritize improvement initiatives.
  • Cost of Poor Quality (COPQ): impact on bottom line.
  • Process sigma value: quality of service status.
  • Failure Modes and Effects Analysis (FMEA): identify risk and mitigate risk through prioritization system.
  • Control charts: control and predict process performance behavior.
  • Pareto charts.
  • Correlation diagram
  • Kepner Tregoe or Ishikawa "fishbone" diagrams: cause and effects analysis.
  • Hypothesis Testing: test/brainstorm potential solutions.
  • Cost/benefit analysis of proposed solution.
  • VOC.
  • Control charts.
  • Process sigma value.
  • COPQ.

Six Sigma focuses improvements on CTQ processes or services that impact customers and the business bottom line. This is a common need and challenge for IT to overcome. IT service management practitioners need to be more integrated with the business and listen to what is important to the business. This in turn will help IT prioritize initiatives, improve IT's value delivered to the business and increase operational effectiveness.

We've covered what Six Sigma is, how it can be applied in the IT service management world and which techniques are useful for IT. In our final article, we will look at how Six Sigma complements ITIL v3 and its new Continual Service Improvement (CSI) phase. Does the new CSI's Seven Step Process compete with Six Sigma? Does ITIL v3 have it all for continual service improvement?

Linh C. Ho is Director of Product Marketing at OpTier Inc. Prior to OpTier, Linh was senior product marketing manager at Compuware, as well as at Proxima Technology. Linh has over 10 years in the IT service management market. Linh is a co-author of two itSMF books: "Global Best Practices for IT Management" and "Six Sigma for IT Management." Linh also served on the review team for several itSMF books, including ITIL V3 Foundations. She has written articles and spoken at conferences on the topics of Six Sigma, ITIL and IT service management. Linh is certified ITIL v3 and a Six Sigma Champion. She holds an Honors Baccalaureate in Commerce; International Business Management and Management Information Systems from the University of Ottawa. She can be reached at

Further reading:

Linh C. Ho has published a Six Sigma Q&A (click here).

itSMF has published a book called "Six Sigma for IT Management" relating to this topic (click here).