Six Sigma is described as a relentless quest for perfection through the disciplined use of fact-based, data-driven, decision-making methodology. Since this should be the ultimate goal of any organization, this is a good start.
So how does Six Sigma improve quality? Six Sigma advocates proclaim that the Six Sigma philosophy is to prevent defects before they happen upfront via process improvements. This is the best way to attack a problem, prevent the conditions that allow it to occur in the first place.
So how does Six Sigma accomplish this task? It uses a toolbox of statistical tools and frameworks to:
- identify which defects impact customer requirements,
- determine why each defect was caused and uncover the hidden factory, and
- improve the process parameters and product designs to reduce defects.
Instead of focusing simply on meeting design specifications, six sigma practitioners look for ways to decrease the overall amount of variation in a process subject to critical target values, since process variation is often the primary cause of defects in a well designed product. Decreasing variation is no simple matter when you consider that variation can stem from variation in your internal processes, inconsistencies in material or information from suppliers, part and product designs that are not robust, and overly conservative design specifications, with both common causes (defined as system faults) and special causes (defined as fleeting events). In addition, these variations can be caused by any of the six Ms: man, machine, material, methods, measurements, and mother nature.
Six Sigma accomplishes this feat by careful application of its DMIAC problem solving methodology and its toolset. DMIAC stands for Design-Measure-Improve-Analyze-Control and the process generally executes as follows:
- define each process step, inputs, and outputs
- map the customer requirements to process inputs and outputs
- identify key metrics to measure performance
- establish defect root causes for, and relationships between, inputs and outputs
- analyze and improve the process to optimize performance metrics
- provide controls to ensure sustainability of improvements
The analysis, root cause identifications, and improvements often come about using one of the following toolsets of a six sigma practitioner:
- pareto principle
- experimental design
- Quality Function Deployment (QFD)
- thought process maps
- process flow charts
- graphical techniques
- cost analysis
- scrap reports
- cycle time fluctuations
- Failure Modes and Effects Analysis (FMEA)
The basic DMIAC process and six sigma toolbox is also the basis for the three fundamental types of innovation projects identified by advocates:
- creating new products, services, or markets
- extensions or feature improvements to products, services, or markets
- increased efficiencies in existing products or services
In other words, DMIAC is quite powerful, but so is any good problem solving methodology when properly applied. Speaking of application, a successful Six Sigma project will always have the following characteristics: strong leadership, clear definition, strategic alignment with the business, (more than) adequate management support, and practical transferability.
Six Sigma projects require strong executive support and support from the functional and project leaders. Incentives must be aligned to insure that they devote enough time to the project. The project must have a clear definition that includes the precise problem definition, goals, “stretch” goals, financial targets, and team structure. The project must be strategically aligned with business objectives and everyone must be on the same page. Management must support the project from inception through completion and it must be transferable to other users and business units.
In short, six sigma requires all of the elements of success that any other improvement project requires, including the dedication and the know-how. It also requires an extensive knowledge of best-practices and best-in-class techniques. It is essentially an evolution of business process management (BPM) best practices that have been discovered since the dawn of the organizational era by operations management researchers. (I will be making occasional posts on operations management on Sourcing Innovation and here is a direct link to a post describing the Operations Research Modeling Process.)
For more information on six-sigma, see the Six Sigma: Improve Supply Chains through Methodology wiki-paper over on the e-Sourcing Wiki.