Six Sigma, or 6σ, is both a methodology for process improvement and a statistical concept that seeks to define the variation inherent in any process. The overarching premise of Six Sigma is that variation in a process leads to opportunities for error; opportunities for error then lead to risks for product defects. Product defects—whether in a tangible process or a service—lead to poor customer satisfaction. By working to reduce variation and opportunities for error, the Six Sigma method ultimately reduces process costs and increases customer satisfaction.
In applying Six Sigma, organizations, teams, and project managers seek to implement strategies that are based on measurement and metrics. Historically, many business leaders made decisions based on intuition or experience. Despite some common beliefs in various industries, Six Sigma doesn’t remove the need for experienced leadership, and it doesn’t negate the importance of intuition in any process. Instead, Six Sigma works alongside other skills, experience, and knowledge to provide a mathematical and statistical foundation for decision making. Experience might say a process isn’t working; statistics prove that to be true. Intuition might guide a project manager to believe a certain change could improve output; Six Sigma tools help organizations validate those assumptions.
Decision Making Without Six Sigma Without proper measurement and analysis, decision making processes in an organization might proceed as follows:
- Someone with clout in the organization has a good idea or takes interest in someone else’s idea.
- Based on past experience or knowledge, decision makers within an organization believe the idea will be successful.
- The idea is implemented; sometimes it is implemented in beta mode so expenses and risks are minimized.
- The success of the idea is weighed after implementation; problems are addressed after they impact products or processes in some way in the present or the future.
Beta testing is sometimes used in a Six Sigma approach, but the idea or change in question goes through rigorous analysis and data testing first. The disadvantage of launching ideas into beta—or to an entire population–without going through a Six Sigma methodology is that organizations can experience unintended consequences from changes, spend money on ideas that don’t end up working out as planned, and impact customer perceptions through trial-and-error periods rife with opportunities for error. In many cases, organizations that don’t rely on data make improvements without first understanding the true gain or loss associated with the change. Some improvements may appear to work on the surface without actually impacting customer satisfaction or profit in a positive way.