We are saddened to report that Professor Dornfeld passed away in March, 2016. If you enjoyed his blog, please consider making a contribution to either of two funds at UC-Berkeley that have been established in his memory.

David A. Dornfeld Graduate Fellowship
David A. Dornfeld Scholarship

Friday, April 29, 2011

Considering the energy of labor - Part 1

Or, looking at all the actors

The last posting ended up with a short discussion about automation vs manual labor and whether or not that should (or could) influence the effectiveness of green manufacturing strategies. It actually plays into the  larger issue of measuring social impacts/benefits/costs of any green manufacturing technology wedge as we move to sustainable manufacturing.

Recall the the "triple bottom line" of sustainability - economic, societal and environmental. This term was, apparently, originally mentioned by John Elkington in 1994 (he called it the 3-P's: profit, people and planet) according to The Economist  and the "people" part referred to "a measure in some shape or form of how socially responsible an organisation has been throughout its operations." The Economist article sums the approach up using a "balanced scorecard" approach and reminding us of the fundamental principle of "what you measure is what you get, because what you measure is what you are likely to pay attention to. Only when companies measure their social and environmental impact will we have socially and environmentally responsible organizations."

I'm fine with that. The measure part is the tricky bit - specially for social impact - but folks are working on that. In Bhutan, for example, a former king introduced the concept of "gross national happiness" (GNH) as part of a way to build an economy in Bhutan that would respect the unique cultural and spiritual values of the country (See Wikipedia,  for example, or the GNP website for details.) This is in contrast to gross domestic (or national) product, GDP or GNP, that are usual measures of progress.

You can even take a GNH survey on line. Other academics and social scientists pursued this line of thinking and have come up with "index values" of GNH comprised of an average per capita of some rather logical components (again taken from the Wikipedia reference above):

1. Economic Wellness: a measurement of economic metrics such as consumer debt, average income to consumer price index ratio and income distribution
2. Environmental Wellness: a measurement of environmental metrics such as pollution, noise and traffic
3. Physical Wellness: a measurement of physical health metrics
4. Mental Wellness: a measurement of mental health metrics such as usage of antidepressants and rise or decline of psychotherapy patients
5. Workplace Wellness: a measurement of labor metrics such as jobless claims, job change, workplace complaints, etc.
6. Social Wellness: a measurement of discrimination, safety, divorce rates, complaints of domestic conflicts and family lawsuits, public lawsuits, crime rates
7. Political Wellness: a measurement of political metrics such as the quality of local democracy, individual freedom, and foreign conflicts

You may recall that in the IPAT (Impact) equation from previous postings, the "impact/GDP" was referred to as our core concern in manufacturing since if we can reduce the environmental impact per unit of product value to the customer we are on the road to improvement. Some disagree that GDP is a good measure of progress. Hence the alternate measures, like GNH.

For sure, a measure of happiness must be employment and reward for that employment - number 5 above. In addition, economic wellness, number 1 above, as well as related mental and physical wellness can be associated with quality employment. But how do we (or should we) factor this into our technology wedge discussion?

In the last posting the question was asked - if a company reduces the amount of machinery used in manufacturing and replaces that machinery with manual labor does that help? The response was typically academic - it's complicated. Clearly there are some products and processes that don't lend themselves to this "conversation." But, for assembly tasks, one might make the argument that more human labor (replacing automation) might produce the product using less energy and resources and, ultimately, making the product easier to disassemble at its end of life. And then we need to consider the quality of the labor (meaning is it dull and repetitive or intellectually stimulating and, for sure, is it free from danger or other safety issues.)

So, this long lead in is to set the stage for a discussion of the "energy of labor." This discussion is based on a paper we published some time ago and included in the recent thesis of the student co-author. The paper, titled "Energy Use per Worker-Hour: A Method of Evaluating the Contribution of Labor to Manufacturing Energy Use," was written by Teresa Zhang in my lab and presented at the 14th CIRP International Conference on Life Cycle Engineering in 2007 and published in the proceedings of the conference "Advances in Life Cycle Engineering for Sustainable Manufacturing Businesses" edited by S. Takata (it's on Amazon!).

Energy is an important metric of environmental impact and manufacturing efficiency. We know that in life-cycle assessment (LCA) analyses, energy consumption as a key parameter that can dominate environmental impacts such as global warming potential, carcinogenic emissions, and acidification potential. Energy assessment is also effective as an indicator of manufacturing efficiency. As yield, manufacturing cycle efficiency, process capability, and other manufacturing performance metrics improve, energy use per unit output decreases accordingly.

The metric of energy use was popularized largely due to the work of Howard Odum, who has written numerous books on energy and environmental accounting since the 1970’s (for example, Odum, H. T., 1971, Environment, Power, and Society, Wiley-Interscience, New York).  In a publication in 1996 (Environmental Accounting: Emergy and Environmental Decision Making, Wiley, New York), he presented several methods of quantifying the energy use of labor, in terms of metabolic energy, national fuel share, national emergy share, and as a function of the level of education enjoyed by a worker. Others have also discussed the energy use of labor in the form of caloric content of food consumed.  Calculated as such,  the conclusion is that the energy contribution of human labor to energy use is negligible. But there is more to the story.

The methodology presented in this posting from the paper is related to economic input-output (EIO) LCA, in that both methods aim to quantify environmental impacts that may not be included in process-based LCA.  Because both methods take a top-down approach, presenting averages for an industry or country, they do so without tremendously increasing the work of LCA practitioners.

Energy of labor and EIO-LCA should not be applied at the same level of analysis because many sources of energy use would be double counted. However, energy of labor can be very effective if incorporated into hybrid process-based EIO-LCA, as shown in the figure below, where EIO-LCA is used to assess activity upstream of the process-based analysis.  The energy use of labor enriches the horizontal scope of process-based LCA, while EIO captures vertical supply chain impacts.


           Schematic of process based LCA and energy of labor used in series with EIO LCA.

In addition to improving the accuracy of LCA, evaluating the energy of labor can be applied to extend the decision making capabilities of LCA.  The energy of labor enables us to quantify and inform decisions that introduce or reduce the degree of automation, deal with the location of a plant, or involve labor intensive process steps.

We'll continue the discussion from here in Part 2 next time.

Tuesday, April 12, 2011

Resource Dieting 2.0


Or,  you are what you eat?

The discussion on reducing resource consumption along with energy and other consumables continues. We are moving, steadily, from 'should we' to 'how can we' and 'how much have we'? This in regards to reduction of impacts for a variety of industries.

Recent Environmental Leader articles tout advancements by an increasing number of major corporations in areas as varied as "commitment to sustainability" to "CO2 from transportation." In the former, sustainability, Unilever, was at the top of a poll of sustainability experts who were asked to identify companies who are "committed to sustainable development, seeing strategic advantage in pursuing policies and actions which go beyond the requirements of environmental and social legislation.” Other companies high on the poll include General Electric and Interface along with Walmart. Do you remember not too long ago when some of these companies, Walmart in particular, would not have been mentioned anywhere near this kind of improvement?

I take special interest in the "seeing strategic advantage in pursuing policies and actions which go beyond the requirements of environmental and social legislation" part. That's leadership and smart business practice.

In the latter example, CO2 emission, the reference is to Maersk Line and reduction in CO2 from its shipping operations. Only down 5% this last year but they are committed to reducing their CO2 emissions relative to a 2007 baseline (and that's before the big downturn) by 25 percent by 2020. One solution - a new class of ships that has 16 percent higher capacity but emit 50% less emissions than typical. That means less fuel for an equivalent tonnage transported. That's one way to reduce the impact per GDP. The Environmental Leader article mentions that they surveyed over 300 customers and found that a large percentage (41%) consider sustainable operation when selecting a carrier and, thus, Maersk, sees this as a competitive advantage.

Less is more - a great philosophy when going on a diet!

Reduced transportation impact help reduce the manufacturing phase impact if the product is heavily dependent on supply chains stretching out a long distance. And that helps move us towards the lower left corner in the use vs manufacturing impact chart.

Again from Environmental Leader (I'm a big fan - can't you tell?!) is another novel example of resource dieting. One of my students, Katie McKinstry, sent me a link to an article from yesterday on Ford Motor Company "turning carpets in to auto parts." The article gives some impressive statistics. It states that "Ford has recycled nearly 4.1 million pounds of carpet into cylinder head covers … [t]he Ford Escape, Fusion, Mustang and F-150 all use EcoLon, a nylon resin made from 100 percent recycled carpet." This, added to the use of soy foam seat cushions and recycled blue jeans for sound-dampening material, shows the potential of reuse of materials from the waste stream and, ultimately, reducing the consumption of virgin materials for these applications. Talk about dieting!

Looks like used carpet is going to be a hot item on the commodity market with Ford competing with carpet companies, like Interface and Shaw, for used carpet.

Finally, also on the theme of dieting, is the question of automation. Let me explain.

If a company reduces the amount of machinery used in manufacturing and replaces that machinery with manual labor does that help? It is complicated. Clearly there are some products and processes that don't lend themselves to this "conversation." But, for assembly tasks, one might make the argument that more human labor (replacing automation) might produce the product using less energy and resources and, ultimately, making the product easier to disassemble at its end of life.

Or not. We need to think about this.

Next posting we'll discuss the "energy of labor" based on a paper we published some time ago and the recent thesis of another one of my students.