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

Royalties from David’s book "Green Manufacturing - Fundamentals and Applications" go to these Funds, too.

Thursday, February 17, 2011

Green Consumption and Green Manufacturing

Or where does the (green) buck stop?

Recent postings have been discussing the connection between the use phase impact of a product and the manufacturing phase impact and what influences these. This was in the context of both looking at means to reduce consumption (meaning giving the consumer products that deliver the required functionality or service but at a lower environmental impact or energy/resource consumption.)

There are a number of places along the product development chain that critical decisions are made that have a positive or negative influence on this impact. Last time we were talking about whether or not the rule of thumb that 20% of the design influences 80% of the cost of a product also applies to the energy/resource impact. I thought that, in many cases, it didn't work that way.

There is, by the way, a great study on this from 1993 written by some MIT researchers (Karl Ulrich and Scott Pearson) titled "Does product design really determine 80% of manufacturing cost?"  and they tease this comment apart with some case studies and analysis. The report attempts to determine how much product design influences the manufacturing cost of a product. They study this for a class of high-volume, electromechanical consumer products — automatic drip coffee makers - and they find "that for coffee makers, the variation in manufacturing costs attributable to differences in product design is slightly smaller in magnitude than the variation in costs attributable to differences in manufacturing systems, for a specific range of assumed manufacturing system parameters." They note that the "rule of thumb" is specially flawed where the dominant cost contributor is the cost of materials. Further, they note that "There is also a basic logical flaw in the argument that if the minimum possible manufacturing cost is 80% of the maximum possible manufacturing cost then product design is a critical activity of the firm. The flaw arises from the assumption that much of the 80% of the cost of the product is under the control of the product designers."

I was not going to get into that but I agree. But, for now, we are concerned with the influence of design vs manufacturing on the life time product energy or resource impact.

So, back to use vs manufacturing impacts. You might recall this discussion recall blogs ago. We can actually visualize this use vs mfg impact space in terms of what needs to be done depending on where the product sits in that space. In the figure below, we can see four quadrants of "sustainable product" characterization.

The axes are the same as in the use vs manufacturing discussion and indicate, from low to high, the consumption or impact of that phase of the product's life cycle. Then the "low-low" quadrant indicates the most sustainable product. The "high-high" quadrant contains products that are to be avoided or, in another sense, offer the most potential for improvement. The two "high-low" quadrants represent products where we need either to increase the efficiency of the product (with respect to design or using manufacturing leveraging) or we need to improve the efficiency of the manufacturing process relative to use and manufacturing phases, respectively.

This figure does not, however, discuss the relative importance of all the phases of the product life referring back to the earlier discussion about the role of design. I've tried to capture this in the figure below. The figure shows the contribution to lifetime impact or energy/resource use of the various phases of a product, from first concept through design and production to end of life.

First, please note that this is a conceptual drawing (even a cartoon) trying to represent reality. There are lots of examples where this likely does not represent real product performance. And, you might be able to adjust the location of the high and low parts of a particular pattern relative to the phase somewhat as well. But, having said that, we can identify at least four patterns of impact shown in the figure as A. B, C, and D.

Pattern A, in blue, is what I think is a typical impact cycle with the major contributions to impact coming in the manufacturing and use phases. Pattern B, in red,  reflects design decisions that more aggressively affect product impact - things like inefficient use of energy based on design decisions/component selection, materials choice, etc. Pattern C, in yellow, reflects an introduced manufacturing process/system efficiency that reduces the manufacturing contribution but has little impact on the rest of the product performance. This might be due to a more efficient process chain for manufacturing.

Finally, pattern D, in green, represents an example of "leveraging" manufacturing. Here the assumption is that a more capable manufacturing process is introduced in the production plan that may consume more energy or resource in itself but offers product advantages in that it improves the performance of the product over its lifetime. The example given in an earlier posting about improvements in automobile engine efficiency due to aggressive use of precision manufacturing is in this category.

An important point to note is that it is the area under the curve that is the cumulative impact of the product - basically the product of impact x time. Meaning, Pattern D is the best in this example since the area under the line representing that pattern is the smallest of all the examples. The worst case illustrated here, in terms of cumulative impact, is pattern B - poor design decisions.

It is possible to have improved manufacturing offset, somewhat, poor design. Pattern C does that to some extent.

Think about these two figures and the decisions that can be made along the product phase from design through end of life that will have an effect on where the product is located in the use vs manufacturing space. There is a lot of potential for reducing the impact of the product.

And, you can tell from the way I've composed these examples that I come from the manufacturing side of the engineering profession! I don't mean to "dis" my design friends in any way. I just want to make sure we are all aware of the tremendous potential manufacturing offers to address the sustainable consumption challenge.

We will continue to work on these "potentials" more in the future.

Tuesday, February 8, 2011

Everyone wants a label

More on sustainable consumption

Last time we started to introduce the issues around sustainable consumption - from a manufacturing perspective. I know this sounds a bit strange, consumption from a production viewpoint, but the idea was motivated by the need to reduce the demand for un-necessary products (or, at least, to minimize the waste created by their consumption) and how manufacturing might play a role in this.

In the impact equation (also called IPAT) the demand is driven by population and consumption per unit of population (usually referred to as GDP/capita). It is this piece that, if reduced, would have a big effect on the overall societal impact on the environment - make consumption more sustainable (or, at least, less impactful).

Previously we discussed how manufacturing helps with the Impact/GDP piece of the impact equation - meaning, manufacturing provides the where-with-all to reduce that piece.

It is not a simple task - but ideas are emerging.

A recent International Herald Tribune article (29-30 Jan 2011) had a page of coverage about the World Economic Forum at Davos and talked about wind energy company Vesta and the wind energy association introducing a special label for products made with wind energy. The label is being promoted by a consortium of international organizations and companies interested in promoting the use of clean energy and they've come up with a symbol, consisting of three blue "swooshes" around the word “WindMade,” as their way of promoting products made with clean energy.

Companies are seeing a slow down in the movement towards reducing climate change due to the economic downturn, new political realities and questioning about the urgency. So, some groups and companies are picking up the torch themselves.

The idea is that if the consumer sees that the product was made with renewable energy they are more likely to purchase it - it aligns with their personal commitments to sustainability, etc.

Never mind that in the last posting I quoted the study by Enviromedia about the current 350 different labels that already confuse the consumer.

But this one, wind energy produced, has the potential to take root. The promoters also indicated there could be labels for other sorts of energy sources for producing the product as well, hydro, bio-fuel, solar, compost methane, etc.

The question is, to rephrase the comment from Professor Lanza in the last posting, do we want to encourage people to buy products they don't need with money they don't have to impress people they don't like and that are made with energy that is better used somewhere else (or not at all)!?

This is the quandary … if you have a renewable source of energy should you be able to "waste it" and still claim to be advancing the cause?

Now, certainly, all the products made with renewable energy are not wasteful and un-necessary - not by a long shot. But it is the mentality that is potentially problematic.

So, how about a label for products made with "green manufacturing" technology (hopefully powered by renewable energy)? Why can't we have a label to represent products that are made with the minimum expenditure of resources (materials, water, other consumables), energy and with benign or, better, positive social impact to the folks making the products? And produced on systems that optimize both production efficiency and energy and resource utilization as discussed in the last posting.

I don't have a specific proposed label here. But we could call it "GreenMade" perhaps.

If you have some ideas send me a sketch! I'll include some of the better ideas in the blog in the future! Maybe a factory made of green leaves? Or a smokestack blowing smiley faces? Go for it!

And what about product design? It is often stated that design is 20%  of the product development cycle but fixes 80% of the cost (see, for example, the article by David Anderson for a reasonable summary of this). The implication is that decisions made early in the concept and design phase for a product will dictate features/requirements that will control 80% of the lifetime product cost. The logic then follows then that it is difficult, if not impossible, for manufacturing to reduce costs since "design determines manufacturability" thus locking in costs.

But this does not necessarily translate to fixing 80% of the energy consumption (or other material/resource consumption). Let me explain.

Manufacturing processes differ in terms of their abilities, and efficiencies, to create functional products or components from raw materials. That is, transforming materials from one form to another - the definition of manufacturing - can be done in many ways. Even for the same design.

Further, the energy a product uses may depend a lot, or only minimally, on design decisions. For example, a designer may pick components for use in the product - say an electronic device -that individually consume a lot, or little, energy and together make the product function. That would count for a design driven energy product profile. Choosing correctly at the design phase would reduce product lifecycle impact.

But, there are many situations where this link doesn't work.

Going back to our "leveraging" discussion some postings ago we saw some examples of manufacturing enabling a design (which was not specifically dictating a process chain to produce the component) that had a tremendous effect on reducing the lifetime consumption, and impact, of the product. In that case the example was an automotive engine.

So, I think we can "decouple" design from manufacturing in many cases in term of energy or resource impact over product lifecycle and consider manufacturing an "independent" variable when it comes to determining life time product impact.

How we do that is a subject for additional discussion - let's continue this next time!