What is Six Sigma?

Simply put, Six Sigma is a rigorous data-driven methodology that aims to improve processes. It does this through the reduction in waste, errors, defects and variability in a process. This results in an overall improvement in the quality of the output of a process, the products or services. Thus, adopting Six Sigma results in lower costs, increased profits, increased quality and improved customer satisfaction.

It was developed in 1980 at Motorola as a way to statistically measure incidence of product defects in the manufacturing process. Six Sigma quality performance means 3.4 defects per million opportunities (accounting for a 1.5-sigma shift in the mean). In other words, 99.99966% of all opportunities in the process are statistically expected to be free of defects. Nowadays, the definition of Six Sigma has been expanded to mean a measure of quality that strives for near perfection. 

How do you implement Six Sigma?

Practically speaking, Six Sigma methodology relies on measurement-based strategies that improved processes and reduce variation in processes through Six Sigma improvement projects. This is achieved through the use of DMAIC-approach to problem solving, to determine what is causing the defects in a process. DMAIC is an acronym for Define, Measure, Analyze, Improve, Control. It is a data-driven improvement cycle that aims at improving processes.

The objective of the Define phase is to identify the goals, business problems and project scope. This phase lays the foundation for the overall project. In this phase, project charters are set up. The project charter clearly defines the benefits to the customers, the skills required for the project, the responsible team members, the project measures, financials and communication plan.

The Measure phase, is concerned with data collection and establishing current process performance baselines from which to measurement improvements. There are two main type of data, quantitative and qualitative data. Quantitative data is numerical data to gain descriptive information about a product or service e.g. the no. of batches produced per hour in manufacturing. Qualitative data is non-numerical information e.g. the outputs from surveys and questionnaires regarding employee satisfaction. This type of data can often provide in-depth information about your product/service.

The purpose of the Analyze step is to determine the root causes of the problems and to pin-point where in the process the root causes reside. This can be achieved via fishbone diagrams, process mapping, value stream mapping. The top root causes are selected and examined further through data collection and analysis. Data is collected to establish the magnitude of the contribution of each of the root causes to the problem using statistical tests such as histograms, Pareto charts, Line plots, Volatility analysis.

The Improve step, as the name suggests is focused on creating a solution to the problem identified. During this phase, the solution is tested, refined and implemented across all business systems. This can be achieved through brainstorming techniques, data-driven leveling solutions, flowed devices, standardized work, complex tools such as DOE (Design of Experiments), PDCA cycles (Plan, Do, Check, Act).

Finally and importantly, the Control phase of Six Sigma methodology, is to ensure all of the improvement initiatives are embedded and sustained. This is achieved via visual and performance management, metrics, KPIs (key performance indicators), SOPs (standard operating procedures), control plans and audits.

What are some Best Practices?

Additionally, the most successful Six Sigma implementations deploy the following best practices:

1) Strong leadership

2) Effective communication

3) Targeted measurable results

4) Data-driven decision making

5) Align Six Sigma projects with organizational goals and objectives

What are the benefits to a Six Sigma Approach?

Six Sigma methodology is an extremely powerful technique to improve processes and outputs from a process. The rigor and discipline involved in this approach increases the chances of a successful project and successful outcome for your organization. A Six Sigma approach will result in processes with less variation, less waste and errors and improved quality. This will result in more efficient processes, lower costs and increased profits. Added benefits of this approach include increased customer satisfaction and increased employee engagement.