Case Study

Large manufacturing facility saves $300K in electricity with Six Sigma project

When I worked at Rockwell Collins (now Collins Aerospace), I became more concerned about the environment, and asked to join the corporate green team that was being established. I wanted to apply Lean and Six Sigma to help the company reduce its carbon emissions. They had just established a goal to reduce carbon emissions by 15 percent in 5 years.

One of the first efforts launched was to get all the carbon dioxide emission data into a common database so the data could be reported on easily, validated and analyzed for opportunities. The database provided the team with a breakdown of energy by facility and energy type by month. It was determined that nearly 80% of the carbon emissions (and cost) was coming from electricity. It also showed that the headquarters facility in Cedar Rapids was the largest user of electricity. WIth the start of the green team, and focus on this facility, I actually relocated from Florida back to Iowa so I could conduct a Six Sigma DMAIC project and be more engaged in the green team.

The headquarters served as the beta site for the two-pronged approach to sustainability implementation: Six Sigma’s data gathering and analysis through DMAIC projects, and lean’s gemba walk, or Go and See approach.

The Six Sigma project started off quickly, identifying a business case of $200,000 worth of savings in six months. That figure made it easy to get
leadership support. The project struggled in the measure phase because detailed electricity data was not available to identify the biggest department users within such a large facility. To overcome the lack of actual data, the project team came up with four different approaches to
determine how to proceed on the project:

  • Employee inputs from maintenance personnel
  • Statistical modeling of the facility (read more about this analysis)
  • Trend analysis of the five-minute increment data from the utility company
  • Manual data collection of the more than 50 electrical substations within the facility

All four approaches pointed to the same opportunity: the heating, ventilation and air conditioning (HVAC) system was running all night and all weekend when hardly any employees were working.

Team members unanimously determined that the best solution would be a setback program, where the HVAC system would automatically turn down the air conditioning at a specific time at night to save electricity. A pilot study was conducted in one section to understand employee concerns, working hours and potential technical issues. One countermeasure from the pilot study was the implementation of a temperature override button in each zone in case employees were working when the temperature was not comfortable.

It took almost one year to complete the rollout across the large facility, but the results yielded more than $300,000 in electricity savings, with an implementation cost of approximately $50,000 for labor and materials.

There were also some more focused energy reduction efforts conducted in departments around the facility. If you’d like to learn more about the Energy “Go and See” events, listen to the podcast episode from June 2016.

You can read more about this project at

A summary of this approach was shared in the September 2014 edition of ISE Magazine:

Another summary of the work was written about in the Fabricators & Manufacturers Association magazine in Sept 2016:


Want to learn more about Lean and Six Sigma tools, and apply them to an improvement projects? Check out these low-cost online courses and certification programs



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