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.

Tuesday, September 28, 2010

Don't be distracted by the shiny bits


Or, is there any there, there?

When ever I am thinking of what would be a good topic to build the next posting around I never have to wait long till something pops up. This time…the peculiar intersection of celebrity and the environment.

Maybe you did not see this (it was hard to miss if you read even the mainline press) but a "musician" (or actually performance artist) named Lady Gaga showed up at a music awards program dressed in a "meat dress." You have to read this to believe it as reported by Ecouture magazine website. So, standing next to Cher wearing something "cher-like" is this celebrity covered in thinly sliced beef. The article comments that "the American chanteuse’s Atkins-approved getup, [was] made entirely of slabs of tenderloin, strip steak, flank steak, and rump roast (about $100 worth of the cheaper cuts, notes one New York butcher)." Who says there is no innovation in the US?!

Normally I'd let this one drop without comment but the firestorm of comments about the "environmental impact" (what about mental impact?!) was interesting. Pundits reacting pointing out the tremendous impropriety of this getup with perspectives ranging from "people are starving and she's wasting meat" to "do you know how much green house gas emissions are contributed by livestock production?" (Turns out a lot - according to a UN Food and Agriculture Organization study reported a few years back - more than transportation.)

If one looks at climate change per ton of protein production (from the Ecouture article) she should have covered herself in peas or soy beans if she wanted to make an environmentally benign statement. Only lamb is worse than beef generating more than 100 tons of CO2 equivalent emission per ton of production.

The fashion industry has had a lot of problems finding the fine line between really sustainable products and the chic eco-fashion that looks good on paper (you know, organic cotton, recycled plastic, etc.) until you realize you could feed a family of 4 in many parts of the world for a year or more on the cost of the item.

Eco-not.

If you think I'm off on this, check out the Hungry Planet images posted on Time Magazine website showing what the world eats. The photos document the typical weekly food expenditures of a number of families around the world in local currency and dollars. The family in Chad spends $1.23 a week. Show this to your kids!

The first reasonable reaction to this whole event, the article and the response is - who cares?! When is the last time something truly significant, in terms of environmental impact (not withstanding the BP Gulf of Mexico disaster) received so much press? Wouldn't it be more useful (not to mention the environmental impact of all those computers on and users browsing the Lady Gaga article) to actually discuss things with a more potential impact?

This is actually sort of "green-washing" in reverse - meaning the trumping up of a minuscule environmentally impactful event or item with absolutely no potential to grow into something larger (do any of you see a trend to meat clothing?) into something important. This is almost worse than actual greenwashing (recall our discussion on this some postings long ago (July 10 of last year to be exact - see the post).

Just like it's wrong to overplay quasi-green (or non-existent green) aspects of a product or solution as part of the solution to sustainability, it is wrong to overblow a stunt act into something indicative of the future of the planet. Let's stay focused on what is actually something or, as they say, when "there is some there, there."

Also, just to clear any incorrect perceptions, I like meat (specially beef). I was born in Wisconsin and am happy to have farmers raising cows for milk and other uses in the food chain. My shoes contain leather. So, nothing against livestock here!

So, back to reality and some "there"!

As a follow up to our discussion about data flows (drinking from a firehouse), monitoring and dashboards for energy consumption, I mentioned that I visited the Bosch-Rexroth booth at the IMTS show the week before. They sent me some images from the display and this gives some substance to my "Google earth view of manufacturing" that has appeared a number of times in this blog (just search for the term in the box at the top of the blog page if you don't remember this.) At the lowest end of the "manufacturing view" was the machine with tooling and process details.

The figure below, from Bosch-Rexroth's MTX CNC Energy and Power Monitor for energy efficiency, shows the monitoring


strategy with the ability to identify the utilization, and losses, associated with power coming in at the bus, output to the motor, output to the mechanical shaft driving the machine tool (moving the workpiece relative to the cutting tool) and to track this in a dashboard, on an axis by axis basis including the consumption of auxiliary components. There is an article on this in the SME Manufacturing Engineering magazine of April, 2010 if you'd like some details. The figure below shows auxiliary consumption for hydraulics, fans/ventilation, cooling unit and spindle cooling.



With this level of detail associated with the process (what am I producing and how are the machine drives responding?) and the auxiliary components (when I'm not producing product what is my machine consuming? Is is worthwhile to shut some of this down while the machine is in changeover or idle?) the machine tool builder can consider alternate stratifies of machine operation and control, and the manufacturer can  (with suitable analysis tools) determine best practices for insuring part quality and minimum energy consumption.

Lots of data but a lot of digestion and presentation so we can handle the deluge...and make decisions.

Now this is worthy of some comments.

To end, I was reading the Economist (September 4, 2010) on a recent plane trip and they had an article titled "Ruses to Cut Printing Costs" with a byline that said "all kinds of technological tricks are being used to reduce the cost and environmental impact of office printers." I was intrigued. Turns out, people are doing all kinds of things to save resources which, for a laser printer (or ink jet), you can try to optimize "print vs toner" by choosing fonts which are thinner and use less toner or ink per character. The article quotes on source as stating that by switching to Century Gothic (which uses less ink) they saved $80/year/printer. The key was noticing that variability of ink/toner required per letter with different fonts!

Another company, a Dutch firm called Ecofont, came up with software to insert into fonts small holes in the letter that are not visible to the eye. This works best apparently on small fonts. They claim to be able to save 25% in the amount of ink or toner used. That's green!

And this is sort of the "office" equivalent of minimum quantity lubrication which reduces, dramatically, the amount of cutting fluid needed to machine a component. I mean reductions from thousands of liters to milliliters. We might discuss this some time in the future.

If your going to print the data from your firehose make sure it has holes in it!

And, finally, last, from the comment section, one commenter asked relative to my posting from the IMTS "did exhibitors or speakers address using the USGBC LEED program helping to provide assurance to end customers of verifiable improvements of manufacturing facilities?" Short answer, I did not see anything on this but, to be fair, was not looking for that angle. The focus of the show was on stuff in the building, not the building itself. Further, most manufacturers are just getting to grips with the operation, or use phase, consumption and not the embedded energy from materials, buildings, etc. used to produce the hardware. But that is coming.

Many companies have started working on the lighting, heating and ventilation, compressed air, etc. plant wide large scale energy consumers. But, there is much to be done. I'll check with some of my contacts to see if there are any examples of successful verifiable improvements. I am sure they are out there. Any readers can send me the contact info and I'll pass it on to the commenter or use the response section in the last posting  to respond directly.


Wednesday, September 15, 2010

Drinking from a firehouse, part 2


The greatest show on earth

This week I am writing from the IMTS in Chicago also known as the "greatest (manufacturing) show on earth" to paraphrase Barnum and Bailey. And it is a bit of a circus. Instead of rings you have several large halls chock full of the latest manufacturing technology (hardware and software) and every vendor who is anyone is here showing their stuff. Lot's of noise (machine and human), lot's of people, it's great.

So, what does this have to do with our firehouse analogy?

Let me elaborate. The "hidden" theme of this show is energy and resource consumption. The concern about energy monitoring, display and decision-making is pervasive. Not in the banner over the booth, but in the displays on the floor. Specially for the large control and motor/driver manufacturers like Fanuc, Siemens, and Bosch-Rexroth. They are all showing technologies for measuring and displaying energy data on controller or dashboards on computers.

Other companies are pushing the application of their machines and solutions to the growing alternate energy market - for example MAG is pushing production of wind and solar components, large and small, and OKUMA has a banner proclaiming "Solutions for Energy." Every one is seeing the push to reduce and the potential for market share in creating the solutions.

And why? Demand from customers, growing business opportunities and/or push back from people using their systems in production.

One of the people I have interesting discussions with about the trends of manufacturing and what's hot and what's not is a principal in a large high precision manufacturing company in the midwest. They have a range of clients from medical device to aerospace and the US Navy. To see their facility is to observe parts being made of tiny medical devices on a "Swiss" rotary transfer machine all the way to cowling components for surrounding the jet engines on the Airbus A380 giant airplane.

They also do work for companies like Johnson and Johnson and when I asked my friend if they are getting any serious push from their customers on energy he gave me a resounding YES!

Johnson and Johnson have a statement on their website, amongst a list of their expectations for the company's environmental performance, that their goal for External Manufacturing (ie my friend's company) is "100 percent of external manufacturers in conformance with Johnson & Johnson Standards for Responsible External Manufacturing by 2010." To date JNJ state that they have "shared our Standards and/or integrated these standards into formal contracts with more than  80 percent  of our external manufacturers by year-end 2007." Performance on the environment in the contract with their external manufacturers!

This means data…data on energy consumption of manufacturing…which means data from machines on performance cross linked to parts…meaning energy data linked to steps in the production of the part including on a line by line basis for the program code driving the machine tool in the case of material removal processes. This adds up to a lot of data - the subject of the last posting.

Recall that we had estimated that sampling energy data values for a "medium sized facility" for a day (here meaning 25 CNC machines, 10 programmable logic controlled machines and assorted other handling and line equipment with 8 data sources per machine at a sample rate of 5 hertz) would yield a data stream of 86,400,000 data points each day. And that if we added the other sources, we'd likely end up with 100 million data values a day to deal with.

So, let's continue our discussion from last time. Data can be related to events and information associated with those events. Thus, data can be understood as something that occurred either at a specific time or over a range of time. In manufacturing systems, events can be a numerical value (for example, the instantaneous power consumption at a specific time) or can be a type of annotation (for example, the alarm state of the machine tool over an interval). Complex events are abstractions of events that are created by combining simple events. For example, based on simple events pertaining to the tool position, the instantaneous power consumption, and the machine tool’s program in machining a part, we can create maps linking power and stages of part production.

The paper I referred to in the last posting describes what is called "events stream processing techniques" that include rules engines (RE) and complex event processing (CEP). These techniques can be used to create higher level abstract events and reason on them by pattern matching and identification. The figure below is an example of software architecture for temporal analysis. This spans multiple data


inputs from several devices, standardized data bus (e.g. MTConnect), and use of rules and complex event processing to create these "maps linking power and production."

My friend can use this to answer J&J's concerns about how much energy they are using to create the products they make. And, we can extend this to water, other resources, or whatever the customer wants tracked. And, knowing consumption is the first step to reduction.

The paper from part one of this posting went on to show the results of a case study applied to an energy
monitoring and analysis framework using energy consumption and process parameter profiles from machining experiments.

But at the show, Dr. Vijayaraghavan (the coauthor on the paper we were discussing in the last posting on data handling) and his company System Insights had a neat demo in the Mazak booth showing the real time implementation of this. On a website you can see, for a number of Mazak machine tools of varying sizes, the instantaneous power consumption. If you click on one of the machine icons you go to a "Mazak Energy Dashboard") for the machine (see below) and get the data, over time periods of


whatever you like for the operation of the machine. You can see total energy use (in kWh), energy cost (for the location you choose - US, Japan, Germany or, in the US, state by state), and "savings" relative to a benchmark machine test in the categories of energy, money (based on cost of energy), Co2 emission equivalent (based on the energy to CO2 conversion for the locality's energy mix) as well as that equivalent in terms of Al cans saved, miles of auto driving or use of compact fluorescent lamps. And, it has in the lower right hand corner an cool real-time power meter readout.

A further chart from that machine window shows real time power plot over time and summary info, shown below for the Integrex i200S Mazak machine tool. The summary numbers are a bit

different in the two figures as I accessed the data on the website at different times as I was preparing this posting. If we dig deeper, as in the figure last posting September 6th on examples of analysis across temporal scales, we can see the ability to correlate power with specific machine motions. That is next on the dashboard.

This starts to convert our firehouse of data into rather manageable mouthfuls!

I visited the Bosch-Rexroth booth and they were showing similar information albeit, in this case, from a specific set of servos driving a machine simulator.

It's happening. Data flows will increase. Are you thirsty?!

Monday, September 6, 2010

Drinking from a firehose


Or, data collection for energy and resource monitoring

I mentioned last posting that I was attending a manufacturing conference in Italy the end of August and that there was a lot more discussion about some aspects of green and sustainable manufacturing - at least efficient use of energy.

This is supported by business surveys and comments in the business press reflecting, I assume, the interaction with business folks "in the know" on such matters. A recent McKinsey special topics report  titled "The next environmental issue for business" gives some interesting statistics on what matters most to business. The report actually was focused mainly on biodiversity and the importance that holds i the minds and hearts of business. We can get back to that topic in the future (and read the report…it is interesting).

I was intrigued by the more general data given in the McKinsey report on issues of importance to business (and based on a responses of almost 1600 survey takers). The top vote getter was "climate change/energy efficiency" coming in at 43%. next in line was "waste/pollution/recycling" with 42%. Following that was "water scarcity/water quality/sanitation at 27%. There are 10 other categories of issues ranging from data privacy to global public health. And, "biodiversity" was 10th on the list. Another "environmental" related concern was toxic materials at 14%. (Note: the respondents ranked a number of issues; so, the percentages will not add to 100!)

I was pleased to see the top three as close to our topic of green manufacturing since they deal with, in order, energy we use and its impact, things we throw away/waste and things from the environment used to make our product besides energy - here water.

Water is often overlooked in all the concern about energy. Not by everyone however! Caterpillar has a goal of "hold[ing] water use flat" as they increase their business listed in their 2009 Corporate Sustainability Report. The website (link to report) gives a short discussion of Cat's plan to determine the "true cost of water" and includes the following statement:

"Without good data it is impossible to justify the cost of water-saving initiatives."

They go on to explain how a program in 2009 at one of Caterpillar’s American plants launched a program "to quantify how much water it was using in its different processes, and the costs associated with water use in each process – including water bills, chemicals, labor, maintenance and energy. The project helped the plant identify its most expensive water processes and associated costs and justified the capital expenditure needed to implement savings."

They plan to extend this program to other Caterpillar facilities in 2010.

Good data … and plenty of it!

Ditto for energy, other resources, etc. throughout the factory.

In the manufacturing conference in Italy I attended, the CIRP General Assembly, I presented a paper co-authored with one of my recent graduate students, Dr. Athulan Vijayaraghavan, titled "Automated Energy Monitoring of Machine Tools." The full reference is "CIRP Annals - Manufacturing Technology 59 (2010) 21–24." (Let me know if you'd like a copy.)

This paper laid out the immense challenges associated with trying to acquire, store and process the streams of data from a variety of machines in a variety of systems throughout a variety of factories. This is done in the hope of, first, understanding where energy (in this case) and other resources (like water) are used and then how to meet the kind of goals the Caterpillar folks are aiming at. This means, understanding the nexus between process operation and resource use to be able to find ways to minimize the use per unit of output. That is, decouple the process and resource equation so we can effectively reduce the "impact/GDP" discussed a few postings back to reduce overall impact of manufacturing.

We focussed on only the machine tool…but the approach can be extended much more broadly.

If you think about making this "connection" between resource consumption and process, you need to first determine the rate of data you need to make the link. For energy, this can range from parts of seconds to hours.

You may recall our discussion some postings ago (January 21, 2010 to be exact) about "temporal vs spatial" aspects of manufacturing. We can create a similar diagram to illustrate this discussion of data rate


demands for tracking energy and resource use. The figure highlights the data rates for machine tools but, for broader sections of the enterprise, you can see the time scale also. The idea is you need sufficiently high data rates to capture the process effects or variability you are trying to associate the use with. Then, we can see how adjusting those parameters or variations can yield savings (without, of course, sacrificing quality or cost.)

Here is another illustration from the paper showing the use of energy in the context of the manufacturing process. The objective is to have data rates "tuned" to the process so one can extract such

            Time scale of data collection for energy use in the context of manufacturing process

information as:

- energy usage per day (lot or batch basis),
- embedded energy during manufacturing a part (piece basis),
- energy used for value-added and non-value-added activities (between productive operations),
- relationship between spikes/troughs and process parameters (details of process operations),
- impact of process parameters on sub-component loads (what's going on around the machine or line), and
- energy used for machining specific part features (related to part design/geometry and functionality.)

This information depends on vastly differing data rates with sampling times varying from milliseconds to minutes.

The data volumes can be impressive. In the paper we give a sample of the number of energy data values for a "medium sized facility" for a day. This facility is comprised of 25 CNC machines, 10 programmable logic controlled machines and assorted other handling and line equipment. For the CNC machines alone, assuming 8 data sources per machine at a sample rate of 5 hertz (5 times/second), we will have a data stream of 86,400,000 data points each day. If we add the other sources, with reasonable numbers of data collection sites and data rates, we would likely end up with over 100 million data values a day to deal with.

Drinking form a firehouse indeed!

So, what's the solution?

The paper proposes a structure for, first, standardizing data (for example using MTConnect), implementing a modular, scalable architecture that supports multiple concurrent data streams and sources and, importantly, employs multi-dimensional reasoning tools.

There is more to discuss on this but this is more than we can cover in one posting. I'll finish the discussion next time.

If you are interested in this approach in the mean time, Dr. Vijayaraghavan has a company working on the hardware and software aspects of this - System Insights. They are already working with a number of companies and will be demoing some of their solutions at the upcoming IMTS (International Manufacturing Technology Show) in Chicago later this month. (In interest of full disclosure, I am an advisor to System Insights.)

By the way, the IMTS is the "mother of all manufacturing shows" and I plan to attend to check out what the view on green manufacturing is from the show floor.

The next blog will be from Chicago!