Friday, January 28, 2011

Sustainable consumption

I am writing this from a technical meeting in Europe I've been attending on manufacturing where the flames of green manufacturing have been flamed and are burning brightly! A separate session on energy efficiency and resource effectiveness saw a group of presentations ranging from more detailed analysis of energy use patterns in production processes (think machining or heat treatment) to more esoteric issues of process planning with energy utilization in mind.

The process planning discussion was interesting. If you are familiar with process planning you already know the complexity of just trying to make sure all machines are used to the fullest extent. Process planning is, basically, how to order the production steps of a product through a number of machines.  It includes how this is optimized to handle the production of a number of different parts (that is, several different sets of parts moving a number of production stations in a sequence - each set of different parts with a different quantity (called batch size)).

Think of the cartoons of production processes shown before here  - a series of boxes linked by transfer mechanisms to move a workpiece from process (box) to process in a sequence. Now think of how a batch of parts of the same component move through this. The first part starts in the first  box where an operation takes place for a set time. Then the part moves to the second box for a second operation and another similar part starts in the first box. With each "cycle" the parts move from box to box until the first part in the batch exits the final box and it is called a "finished product."  Over time, all the parts in the batch move through the production line and the line "falls silent" as the last part moves through the system.

The "falling silent" part is the issue here.

When the next batch of parts (of a different component requiring different times at each of the boxes due to the operations that are needed) starts the production line, the planner has to allow enough time between batches so that the second batch does not "run into" the batch that precedes it. This occurs when the cycle time of some of the boxes is shorter for the second product than for the first one. That is, for a given process applied to a given part, it may require different times to complete the work on a part based on the requirements of the part. And the requirements will change from batch to batch for the parts in the production line.

Further, in such a production line there is always one process that takes longer than the others (called the "bottleneck"). Then, the time in the other steps following the completion of the tasks in that box while waiting for the bottleneck to complete its work is referred to as idle time. The bottleneck may occur at a different station for each batch of parts.

Still with me?

Now, recall the discussion we had in a previous posting on "green at the process level". This identified machines that used energy pretty much independently of the process that was being performed (referred to as "tare heavy") as opposed to machines that used little energy except when performing productive work ("process heavy"). If the production line described above has a lot of stations waiting for a part to appear in order to operate on the part, and the process in the station is "tare heavy", then a poorly planned production process chain will waste a lot of energy while not doing anything productive. Not a desirable situation.

It turns out that a lot of manufacturing processes fall into this category unfortunately for a variety of reasons we won't go into yet.

So, back to the meeting, if one can include in the process planning the consideration of not only delay times (or idle times) in the sequence of starting batches of products (with varying cycle time requirements) but the energy value of that wasted time (do to the machine energy use even if not processing - which will vary from process/machine to process/machine (or box to box in this example), then one could try to find a sequence of production of several batches of products that would insure both minimum production time (or makespan - the time difference between start and finish of a sequence of jobs) and minimum energy used.

This is an industrial engineer's dream problem (and a nightmare to solve).

But, for an existing production facility, for which the processes are well characterized from the energy perspective, this is a realistic goal. A presentation at the meeting by Professor John Sutherland of Purdue University went into some of the details. We can discuss this more at a later time.

So, what about the consumption title of this posting?

At the meeting, following this (and several other) interesting presentations, a discussion started about how if we could just get people to buy more sustainable products, we could produce less overall, and manufacturing would be reduced (although the value of manufactured products would likely be the same or greater) and this would be a better solution than trying to squeeze wasted energy  (or other resources) out of the manufacturing process.

Or as Professor Gisela Lanza of Karlsruhe Institute of Technology put it to me - we need to encourage people not to buy products they don't need with money they don't have to impress people they don't like!

The assembled engineers quickly agreed that we are not into "social engineering" and that this "behavior change" is better left to experts (rock stars, politicians, marketing consultants, other bloggers, etc.)

But, trying to improve the longevity of products by design and manufacturing is something we can aspire to. And maybe the people will follow.

I am encouraged by the fact that Americans seem to be looking for help to do this. Unfortunately they are not getting much assistance from the market place. A recent article posted by Enviromedia commenting on the Federal Trade Commission (FTC) closing its public comment period for its Green Guides states that research that shows 65 percent of Americans would prefer just one seal for green products over the hundreds that are now causing confusion. They note that it is increasingly hard to determine if a product is "truly green" or not based on available information. They are presently overwhelmed with the 350 product certifications that currently exist.

So, the consumer may come around.

In the meantime, there is much to be done to reduce the impact of manufacturing  on the individual process level (and to reduce tare consumption).  This relies on such planning schemes as discussed above. If you have sufficient time between products coming into each box you may actually be able to shut off the process/machine (or essentially put to sleep major components) when the processing is done for that part. Then, if you can restart and warm up the process/machine before the next product appears at that station (box),  to some extent you can "decouple" (a word engineers like to use to mean separate the effect of one thing on the other) the energy optimization problem from the wasted time problem.

And, of course, we can always try to reduce the tare consumption by design of the machine and its control and operation.

We are going to talk more about design and energy efficiency and longevity in the next posting - also motivated by discussions at this meeting.

Friday, January 14, 2011

"Resolution motivators" for the New Year

Thoughts about green New Year's resolutions

With the turn of the calendar announcing a new year I remembered, as a kid, the flurry of activity in my house around the development and pronouncement of New Year's resolutions - those idealized goals for the next year which, if watched but not too closely, made the start of a new year enjoyable.

So I was thinking about this while reviewing a lot of material in preparation for this posting. And, it occurred to me, there are "resolution motivators" that we can use to help each of us craft our resolutions with respect to sustainability and green manufacturing for 2011.

So, here goes.

In no particular order, my top 10 "motivators" are:

1- "You snooze … you loose": The standard phrase employed when someone is not keeping their eye on the ball and gets bested, scooped, left behind or otherwise trumped by someone else. Think large lethargic corporations comfortable in their business practices while their competitors watch the trends and changes and respond resulting in increased profitability, market share and, at least, continuity in business. Reading any of the sources of green technology and business practices shows us that our competitors are not sleeting. Stay competitively awake.

2- Avoid "technical dickies": Definition - when I was in high school there was a "dickie craze." Dickies are faux turtleneck sweater necks (and a bit of shoulder) that you can wear under a shirt to give the appearance that you are wearing a full turtleneck sweater. They are the sweater equivalent to the clip on tie. Whereas they may appear to fool some … they eventually are apparent for what they are (a fake item). Green washing is, to me, the equivalent of a "technical dickie" - something that is not what it appears to be and only fools other "dickie" wearers. Don't green wash. (If you are not familiar with the greenwashing term see the July 10, 2009 posting)

3- "Every one wants to drink milk … but no one wants to milk the cows": This is a saying I got from my old friend Professor Dick DeVor of the University of Illinois. And he got it from his late father-in-law, farmer Herb Luedtke. Country wisdom. We all have to put something in to get something out. That is the reason for the social element of the triple bottom line of sustainability and, frankly, just common decency and good sense. A corollary to this is the familiar "no such thing as a free lunch."

4- The golden rule - "them with the gold makes the rules"; This was a well worn saying of one of my old, now departed, Berkeley colleagues Joe Frisch. It can actually be a positive concept. Consider Walmart (or any other very large corporation with a lot of sway over their suppliers).  Walmart has embarked on a mission to green up their supply chain. Working with the Sustainability Consortium at Arizona State University and the  University of Arkansas they are using their marketing leverage to drive the creation of eco labels for products sold in their stores so consumers can make decisions about what to buy. And they've been proactive about reducing packaging waste. Using your leverage to make things happen.

5- "Why worry about future generations? What have they ever done for us?" Attributed to Groucho Marx. This is the mantra of the "me generation" and has contributed to much of the situation we find ourselves in today. Sustainability, as we have discussed many times, is insuring the future has the same, or better, opportunities that we have. Same opportunities for education, life style, health, freedom, leisure, employment, nourishment and so on. Tall order. But that's what this is all about.

6- "Lead, follow or get out of the way": (and see number 1 above). There is probably nothing more frustrating about someone who is intellectually, or competitively, asleep than if, also, they are blocking your way. I had a friend who used to refer to a mythical "intellectual hat pin" (another relic from the past) that they would employ to poke someone to get someone to start taking some action or, at least, wake up and get out of the way. Leaders have special responsibilities (see numbers 1, 2 and 5 above). Maintaining an open and responsive attitude towards new drivers for reducing impacts in their operations and enterprises is at the top. And then taking action is next.

7- "Live life like a pizza … one slice at a time": I never quite understood this one but it is on a billboard along Interstate 80 outside of Dixon Ca advertising an Italian restaurant. I have other versions of "living life like a pizza" but won't bore you with those. This reminds me of technology wedges. These tech wedges (see September 15, 2009 blog) if this does not ring a bell) are designed to make small, but measurable, reductions in impact or consumption in a process or system. Rather than trying to eat the whole pizza in one bite, take small slices and make measurable, but consistent, progress.

8- "You cut and I pick": This has to be one of every mother's standard instructions in the face of siblings trying to divide like a pie or donut or something else they'd both rather eat all of. One slices and the other then gets first pick of their piece of the pie, or whatever. This insures that the "divider" will do their best to cut the item as close to equal in half as theoretically possible to insure the "chooser" gets a fair shake.  Or, unless the chooser is asleep, the divider loses out. Be fair in your appraisal of any new concept or idea … just as if you were the divider.

9- "This will come in handy if we never use it": This was a phrase often employed by my father, reflecting his depression era "save it" mentality when any item or object came up for disposal but it seemed to have some inherent value or usefulness. He was not a hoarder by any means. But he did know how to get the most out of anything. The "low hanging" (if you will) energy or resources in any factory or facility ripe for saving/reducing/reusing is usually very large indeed. Find it and save it. As Ben Franklin would have said "A kilowatt saved is a kilowatt earned."

And, finally

10- Don't rely on the "magic 8 ball" or similar schemes for your planning.  Read, think, ask, try. There are a lot of resources out there, specially now on the web, put together by folks who spend a lot of time scouring the world looking for innovation, examples, etc. - read them! Some of these sources are listed at the bottom of this page. Google search is an amazing tool. But read, think/analyze, then act.

Thanks for reading along. I hope this provide some stimulation for your resolutions this year.

And, Happy New Year!