A Six Sigma Process Improvement Methodology
Before I discuss Lean I’ll quickly cover the fundamentals of the two contributing approaches, Six Sigma and Lean.Six Sigma is typically defined as a disciplined, statistical approach aimed at increasing profitability by reducing defects. There is a large Six Sigma “tool box” of analytical, data-driven approaches that help companies improve quality in this way.I tend to think about Six Sigma more holistically than many of its current adherents. I also take to heart a comment made by Bill Smith, the Motorola engineer who invented Six Sigma: “If you want to improve something, involve the people who are doing the job.”
So I see the power of Six Sigma as greatest when it is thought of more broadly, as an organizational shift wherein employees use a disciplined approach to improve overall business performance, using data and focusing on controlling process variation. This is even more powerful when built into a Strategy Execution approach, so that improvement efforts are focused on the most strategically important problems for the business.Like Six Sigma, Lean has its roots in manufacturing, but where Six Sigma is aimed primarily at defect reduction, the focus of Lean is on reducing waste (to increase speed). It started as the Toyota Production System (TPS), developed by the Toyoda (now Toyota) Motor Corporation. Toyota’s engineers adopted ideas from Henry Ford (inventor of the assembly line), Frederick Taylor (inventor of modern management techniques and Industrial Engineering), and Dr. W. Edwards Deming (father of Modern Quality Management).
Based on these beginnings, Lean techniques were refined, honed, and improved in all areas into what they are now: a unified, comprehensive set of philosophies, rules, guidelines, tools, and techniques that improve and optimize distinct processes to remove all possible wasted steps, bottlenecks, incorrect materials, etc. It really boils down to improving speed and efficiency.Both methodologies have moved beyond their manufacturing origins and are now used extensively in service organizations, as well as other industries. And both Lean and Six Sigma bring a variety of very useful tools to the table. However, both must be paired with cultural changes and an ongoing focus on process improvement and strategy execution to make a real impact.
Problem Solving Process
By combining these two approaches into Lean Six Sigma, the “tool box” is greatly expanded, including methodologies that are appropriate to solve any given process problem. It brings together the best of both approaches to end up with better quality, faster. It can also make the problem solving process a little easier to approach systematically (even some pretty advanced students of performance improvement can sometimes find themselves in a conundrum about which approach to use — Lean Six Sigma brings them into a cohesive approach).An application of Lean Six Sigma in the service industry is a problem that most hospitals and health systems have, which is a lengthy, inefficient process for discharging in-patients. In this case, the problem is twofold: the cycle time of the process is too long and the process experiences huge variation.
So, the initial thought might be to use Lean tools (map the process and identify bottlenecks or areas of waste). Some of the bottlenecks and waste may be eliminated via common sense of the people who work in the process.However, in addressing other contributing parts of this problem where the solutions are not so apparent, Six Sigma analysis tools will be helpful (one might use a fishbone diagram and then a scatter diagram for analysis and root cause verification, for example).In fact, in a situation just like this, I know of one hospital that used these tools and improved cycle time by 74 percent and reduced variation by 70 percent.Are you using Lean Six Sigma approaches? Tell us about your own challenges or successes.