Key Points

• Lean Six Sigma combines waste reduction and data-driven process improvement to cut rework.
• By eliminating process waste and reducing variation, Lean Six Sigma boosts speed and consistency across production workflows.
• Success with Lean Six Sigma isn’t just about using the tools, but also adopting the core principles as a driving force in your corporate culture.

For modern manufacturing, efficiency and precision are just part of the equation when it comes to profitability. That said, despite the technologically advanced production environments we see in manufacturing, defects and rework are still a pressing concern. Both can erode profit margins, delay deliveries, and test customer trust. As such, manufacturers are asking themselves what they can do to maximize the opportunities presented in their workflows.

Lean Six Sigma is a fusion of Lean’s waste-reduction focus coupled with Six Sigma’s data-driven approach to process control. It makes for a critical and essential framework for making production work for you, while making the most of your resources. Today, we’re looking at some of the practical reasons your organization might want to make the switch to Lean Six Sigma.

The Cost of Rework

Rework is more than a mere inconvenience, instead posing a significant drain of both personnel and financial resources. Poor quality can eat up a chunk of any organization’s annual revenue, with some estimates placing it as high as 20%. Each defect has to be corrected in manufacturing, which adds unplanned labor usage, material waste, and schedule disruptions. Rework also continues to compound inefficiency, as those skilled workers are being drawn away from value-added work to remediation, which compounds down the production line.

Rework’s associated costs are often buried in the operating expenses of any organization’s financials. Overtime wages, expedited shipping, or even increased quality control inspections can occur. It creates a factory within a factory, as rework continues to consume vast amounts of resources without improving throughput or bolstering customer satisfaction. As such, it becomes important to address rework, and it goes further than more exhaustive quality control measures. To make the most of your production workflow, it takes fundamental, systemic change at the process level.

Eliminating Waste at the Source

Lean centers around the elimination of seven forms of waste: defects, overproduction, non-utilized talent, waiting, transportation, and motion. Out of the aforementioned wastes, defects are the most visible while also being the costliest. Approaches like Kaizen, or continuous improvement, Poka-Yoke, or error-proofing, and Jidoka, or automation with a human touch, directly target the causes of rework by developing standardization and detecting defects early.

As an example, implementing simple Poka-Yoke devices, or mechanisms that prevent incorrect assembly or component placements, helps to drastically curtail the amount of rework done downstream. Further, Value Stream Mapping lets an organization visualize the entire production workflow, taking a closer look at bottlenecks, redundant steps, and other considerations that might obscure the true sources of errors and defects.

Reducing Variation and Increasing Consistency

While Lean seeks to eliminate waste, Six Sigma concerns itself more with consistency in production. This is done by minimizing process variation, which in turn reduces the likelihood of defects arising. Data is at the core of the Six Sigma way of doing things, often aided by the DMAIC framework. DMAIC, or Define, Measure, Analyze, Improve, and Control, allows teams to find the source of defects at their origin. Further, DMAIC allows any team to more closely analyze process performance, often in terms of defects per million opportunities (DPMO). From there, you can implement lasting control measures that prevent these defects from recurring.

For another simple example, root cause analysis, making use of Six Sigma’s Ishikawa diagrams or Failure Mode and Effects Analysis (FMEA), lets manufacturers get past things like superficial corrections and focus on the work that matters on a systemic level. These tools convert gut feelings into data-driven insights, which only help to guarantee that remediation is targeted and measured for future process improvement projects.

Lean Six Sigma in Practice

Making use of Lean Six Sigma provides a complete means of reducing rework and eliminating defects. Lean helps to accelerate process speed by eliminating waste, and Six Sigma helps to guarantee process stability and consistency. When used together, this allows organizations to make quality the central target in production, rather than attempting to correct issues as they arise.

Consider the aerospace industry for a moment. Lean Six Sigma has been used heavily for years at this point, helping to increase precision and reduce defects substantially. DMAIC projects focused on reducing torque variance when installing fasteners, as an example, will be combined with Lean’s redesigns, which allow for precision and flow. This only serves to cut rework costs and improve overall reliability when meeting customer-imposed deadlines.

The automotive industry exhibits similar uses of Lean Six Sigma, with similar levels of success. Standardized work is key, especially when considering the international operations of some manufacturers. Statistical Process Control is a key consideration here, as it helps to reduce items like weld rework rates. The proper usage of such a powerful tool can see an automotive manufacturer saving hundreds of thousands of dollars per year through simple adjustments as to what is and isn’t acceptable before shipping.

Cultural Change and Continuous Improvement

One of the bigger misconceptions surrounding Lean Six Sigma is that it is just a set of tools or approaches. Lean Six Sigma does provide these, but it only goes so far without some adjustments to your organization’s culture. Under Lean Six Sigma, your front-line employees should be able to recognize defects and be empowered to halt production if necessary. Further, regular Kaizen events help to foster a culture centered around continuous improvement. You aren’t just seeking to eliminate defects, but rather make it part of routine daily operations. You’re building a better future, one that is centered on incremental, gradual changes rather than the occasional initiative when things go wrong.

Other Useful Tools and Concepts

Ready to start your work week right? You might want to take a closer look at how Kanban can be utilized for drastic productivity gains. Kanban is a means of visually managing work, which is often aided by limiting the current items in progress. When properly utilized, you’ve got the means to see productivity soar while minimizing employee fatigue.

Further, you might want to learn about how Lean is helping to give organizations a competitive edge when it comes to the product development cycle. Lean’s focus on waste reduction only helps to bolster the speed and efficacy of product development, an absolute must when considering the tempo of current manufacturing requirements.

Conclusion

Rework isn’t just a sign of poor quality, but rather a sign that you’ve got inefficiency at the core of any process. Lean Six Sigma offers a structured, data-driven methodology to address these inefficiencies by giving you the speed of Lean and the precision of Six Sigma. You’re not just getting fewer defects and lower operational expenses, but you’re also developing a more resilient organization capable of sustaining long-term excellence.

Modern manufacturing requires speed and precision, especially when faced with competition. Organizations effectively utilizing Lean Six Sigma aren’t just reducing rework, but they’re defining what manufacturing excellence is.