Balancing Quality and Sustainability

Methodology incorporates unit process modeling and life-cycle inventory.

It isn’t easy for manufacturers to balance the well-being of employees, customers and the community all while producing a quality product and staying economically competitive.

Fortunately, a new sustainable development methodology could help manufacturers assess their economic, environmental and social impacts simultaneously.

Researchers at the Oregon State University College of Engineering have created a methodology that incorporates unit process modeling and life-cycle inventory. This allows them to quantify a selected set of sustainability metrics and ask practical questions about them.

These questions include:

  • Should the product use a different material?
  • Would running the production line faster be worth the extra energy used or the impact on worker health and safety?
  • Which approach might lead to injuries and more lost work?
  • How can scrap and waste be minimized?
  • Which design alternative will generate the least greenhouse gas emissions?

The Balancing Act of Manufacturing

The idea behind this research goes back more than twenty years to an international discussion at the United Nations Conference on Environment and Development. The conference raised concerns about the growing scarcity of water, the depletion of non-renewable sources of energy and health problems in the workplace.

“With current tools you can analyze various aspects of an operation one at a time, like the advantages of different materials, transportation modes, energy used, or other factors,” said Karl Haapala, associate professor of engineering at OSU.

“It’s much more difficult to consider all of them simultaneously and come out with a reasonable conclusion about which approach is best,” Haapala continued.

Bevel Gears as a Test Case

In order to test their methodology, the researchers used a series of hypothetical bevel gear alternatives.

One of the hypothetical bevel gears. This one is made of solid steel. (Image courtesy of Oregon State University.)

One of the hypothetical bevel gears. This one is made of solid steel. (Image courtesy of Oregon State University.)

Their six-step system considered energy consumption, water use, effluent discharge, occupational health and safety, operating cost and other factors to evaluate the use of different materials and manufacturing processes.

The most sustainable of the hypothetical bevel gears was then identified with mathematical modeling.

Another hypothetical bevel gear. This one is mechanically joined with a strong steel gear and lighter weight titanium shaft. (Image courtesy of Oregon State University.)

Another hypothetical bevel gear. This one is mechanically joined with a strong steel gear and lighter weight titanium shaft. (Image courtesy of Oregon State University.)

“There’s usually more than one way to build a part or product,” said Haapala. “With careful analysis we can identify ways to determine which approach may have the least environmental impact, lowest cost, least waste, or other advantages that make it preferable to a different approach.”

The researchers believe that their approach, once tested further, should be applicable to a wide range of products during the design decision-making process.

For more information, check out the article published in the Journal of Cleaner Production.