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Applying Lean Six Sigma in the Auto Manufacturing Sector

Written by Danielle Yoon | Nov 17, 2020 5:40:20 PM

As you might guess from the name, a Lean Six Sigma methodology combines Lean manufacturing principles and those of Six Sigma. This approach to production management is popular in the automotive manufacturing industry. Although there are a few areas of caution, the methodology has helped Ford, Caterpillar, General Motors, Goodyear, and many more achieve their quality and value goals.

What Does Lean Add to the Equation?

Lean is a process of continuous improvement based on increasing value for the customer. The goal is to eliminate anything that does not contribute to what a customer is willing to pay for. This means focusing on eliminating waste and streamlining the process of delivering the product.

In automotive manufacturing, Lean involves applying several principles and techniques that include:

Kaizen: The idea that continuous improvement should be based on employee suggestions.

Kanban: Customer demand "pulls" the product through the production process when needed without excess inventory.

TQM: Total quality management continually improves product quality.

5S: Quality and efficiency are improved through workplace organization.

Poka-yoke: A process for eliminating the possibility of errors.

Lean's main emphasis is on cutting out every unnecessary and wasteful step so that only the activities that directly add value to the product remain.


What's Six Sigma's Role?

Six Sigma is a quantitative methodology that focuses on improving quality in auto manufacturing using data collection and measurement to eliminate errors and variation. The expected result is improved product quality. The heart of Six Sigma is the DMAIC improvement cycle.

DMAIC is the acronym for the five steps used to improve an existing process or product. They are:

Define: The cycle starts with the definition of the target problem or process.

Measure: Next, baseline data about the current system or process is collected.

Analyze: With data in hand, the next step is to analyze it to identify the problem or error's root cause.

Improve: This stage involves designing and implementing changes that will eliminate the error. Some techniques used at this point are design experiments, poka-yoke, and standard work.

Control: The cycle is complete when there is a system in place that allows monitoring and making adjustments to maintain and improve on what was accomplished.

In many ways, the objectives of Lean and Six Sigma are the same, with Lean having a broader scope and Six Sigma laser-focused on eliminating errors and improving quality. However, both are based on the foundation of customer value.

Working Together in Lean Six Sigma

The differences in Lean and Six Sigma are why they make so much sense together for all manufacturers, but particularly in the automotive sector. For example, the two approaches have similar goals, but they use different ways of identifying the root cause of waste and errors. Lean looks to optimize production processes, while Six Sigma eliminates waste that results from variations (errors) in the processes.

Another significant difference is that Lean is a bottom-up system, in which opportunities for improvements flow up from the people doing the production work. Six Sigma is a more top-down method using experts to collect, analyze, and act on collected data. Using both provides different viewpoints that identify problems the other did not recognize and suggest solutions the other had not considered.

Lean Six Sigma methodology is effective because the two methods work together to identify errors and waste more efficiently than using just one approach.


Results of Lean Six Sigma Methodology

Applying Lean Six Sigma methodology in auto manufacturing organizations has many positive results, such as:

  • A renewed focus on the customer can deliver value to both the customer and the organization implementing Lean Six Sigma methods.
  • Waste represents an unnecessary expense. By targeting waste directly while at the same time targeting variation and errors, waste is more effectively eliminated.
  • Problems of all kinds are brought to light. Root causes are identified, and the issues are resolved effectively and efficiently.
  • Products are delivered defect-free, economically, and on time.
  • Waste elimination, error elimination, and customer focus become embedded in the culture of an organization.


The automotive sector faces an unprecedented need for innovation, a hyper-competitive landscape, and rapidly changing customer preferences. If ever there was a time and place for the Lean Six Sigma methodology, it is here and now for auto manufacturers.