OR/MS is the application of logic and mathematics to a real-world problem, in such a way that the method used does not get in the way of common sense. –Gene Woolsey

The quote is one of many gems from the book The Woolsey Papers, a collection of Gene Woolsey’s articles, edited by Richard L. Hewitt, mostly out of Interfaces from the early 1970’s to the early 2000’s. Woolsey is an OR professor at the Colorado School of Mines who strongly emphasizes the practical side of OR. He is known for having his students go out and work at the locations they’ll be consulting for. Stories in the Woolsey Papers include several examples of this such as driving a fork-lift in a beer warehouse, food/beverage delivery truck driver-salesman, etc. In many of the stories, the solution is more about understanding how people interact with their jobs, than with complicated mathematics. This gets pretty extreme in one of the stories with a tool clerk pointing a .44 at a factory bully to get him to use a check-out form - more action than your typical OR article.

In a way, the book reads a little like a Surely You’re Joking Mr. Feynman in how entertaining it can sometimes be, and in how the reader gains much more insight into the personality, experiences, and viewpoints of the writer than would be the case from a textbook. Being a collection of articles, there is some repetition, but I mostly liked that; it helped the lessons sink in. It is also short and fairly inexpensive. For all of these reasons and of course for the content (described more below), it could serve as a good companion text for an Operations Research course, particularly a project-based one.

There is great advice on getting practical experience:

If you have no experience, get some. If you don’t know where to start, call your county commissioner or mayor; tell him that you would like to give a free short course on fundamentals of OR/MS to anybody that might want to come. Tell him that you will cover some simple-minded methods that might help someone lay water and sewer lines more cheaply, route school buses better, assign people to jobs more efficiently, cut down materials inventory by finding better reorder points, etc. He will usually want to know why you want to do this. Tell him. Sooner or later someone will let you try.

Now if your tastes in application areas run towards sustainability, this is a great time to find opportunities. Sustainability committees and the like are forming on the local level on up to the federal. Universities, non-profits, and companies are also filled with these kinds of efforts. The decision-making tools (both common sense and mathematical) of the OR practitioner can be a great help to the committee. At the same time, the work provides a great opportunity for the OR practitioner’s education in these areas. It can be done.

Another piece of advice from the book that can be tailored to OR/Sustainability is to seek out knowledge from an application area by finding a professor from that specialty and educating each other, by attending conferences of professional societies in that field, by writing for its journals, etc. Go interdisciplinary. For sustainability there are many fields one could focus on: alternative energy, waste management, recycling, energy efficiency, remanufacturing, green buildings, etc. As for journals, there are undoubtedly many. Here are a few: International Journal of Global Environmental Issues, Renewable and Sustainable Energy Reviews, Sustainability: The Journal of Record.

Whenever Woolsey consulted for governments, he did so for free. In a more recent piece (July-Aug’07 issue of Interfaces) he wrote:

In short, I worked for free, so I could work for money, with some hope of gain, so I could afford to choose which pro bono project would be the most fun to do next… This is the tip of the iceberg of what we have done for ourselves and for our state and community. What are you doing for yours?

Next time: an application of some of the ideas in the book

Here are some more references loosely organized by topic (reverse logistics, waste flow, CO2 emissions tax/trading), plus mention of an old special issue (a 2001 OR Spectrum). The plan is to ultimately get the References page organized by topic.

• Reverse logistics
  • Reverse Logistics: Quantitative Models for Closed-Loop Supply Chains
    Dekker, Rommert, Moritz Fleischmann, Karl Inderfurth, Luk N. Van Wassenhove, eds.
    2004. Springer-Verlag, New York. 436 pp. $109.00.
    Notes There is a review of this book in Interfaces, looks like it might be useful.
  • The Impact of Product Recovery on Logistics Network Design
    M Fleischmann, P Beullens, JM Bloemhof-Ruwaard in Production and Operations Management, 2001
    Notes: Looks good, about facility location problem, has a large formulation then runs the model on a real example of copier recovery. Mine its references. 67 citations. Found the Jenkins (see below) in it.
• Waste Flow (classic)
  • Parametric Mixed Integer Programming: An Application to Solid Waste Management
    Larry Jenkins in Management Science Vol. 28, No. 11, Nov., 1982, pp. 1270-1284
    Notes: Referred to in Fleishmann paper above, it’s old (classic?), has some good references of its own within, and does mention alternate streams for some waste (such as using as a “substitute for coal in cement plants and thermal electric generating stations. It is called refuse-derived-fuel (RDF).”). The main slant of the paper, though, is methodological - a method for sensitivity analysis in MILPs. I listed 2 refs from within below, could look through the others as well.
  • An Analysis of Solid Waste Transportation and Disposal Alternatives
    by HARVEY, D. J. AND O’FLAHERTY, T. G. in INFOR, Vol. 11 (1973), pp. 187-200.
    Notes: Referred to in Jenkins paper above, looks interesting but am having trouble finding it (cga lib doesn’t have the journal).
  • Mathematical Analysis of Solid Waste Collection
    by MARKS, D. H. AND LIEBMAN, J. C., Bureau of Solid Waste Management, U.S. Department of Health, Education and Welfare, Washington, D.C., 1970.
    Notes: Referred to in Jenkins
• CO2 emissions tax/trading (see this previous post on carbon and RGGI)
  • Profit-maximizing R&D in response to a random carbon tax
    by E Baker, E Shittu in Resource and Energy Economics,, 2006
    Notes: There was a corresponding talk in the INFORMS 2007 program.
  • Analyzing the Long-run Impact of the Regional Greenhouse Gas Initiative on the Maryland Power Sector: Oligopoly Analysis
    by Chen, Yihsu; Burtraw, Dallas; Hobbs, Benjamin F.; Kim, Soora; Palmer, Karen; Paul, Anthony; Gabriel, Steve (UMd.);
    Power Engineering Society General Meeting, 24-28 June 2007 Page(s):1 - 8
    Notes: Abstract available here, also presented at INFORMS 2007. This search yields even more related papers. Co-author Hobbs has a large number of papers that could probably be added to the overall references as well.
• The February 2001 issue of OR Spectrum covered environmental management. See table of contents. Here a few of the paper titles/authors:
  • Environment-oriented project scheduling for the dismantling of buildings
    by Frank Schultmann and Otto Rentz
  • OLAF – A general modeling system to evaluate and optimize the location of an air polluting facility
    by Jörg Fliege
  • Life cycle activity analysis: logistics and environmental policies for bottled water in Portugal Life Cycle Activity Analysis
    by Fausto Freire, Sten Thore and Paulo Ferrao

1. Pollution Prevention and OR. It was last updated over 10 years ago, but the NPPC IE/OR Resource List web page has a good collection of references. The page heading says pollution prevention, but many of the references are on other environmental topics. Some are from the OR literature (including EJOR, Operations Research, and OR/MS Today) while others are from more general sources. Likely worth following up on. Housed at the University of Michigan, the NPPC appears to have been superseded by the Center for Sustainable Systems (CSS). The CSS has an extensive website. It has an industrial ecology emphasis but also appears to be highly interdisciplinary, including connections to the OR realm. If you’ve ever gotten a Stonyfield Farm yogurt and wondered how they decided to ditch the plastic cap, apparently CSS was behind it (see image below). See their “Accomplishments” brochure (pdf) for a quick run-down of what they’ve done.

2. OR50 Program. The program for OR50 is up and may be worth scanning as it contains some sustainability talks including a few on wind power and
an OR-Sustainability debate (see this earlier post).

3. INFORMS is a “Green Publisher”
From an INFORMS email:

INFORMS is classified as a “green publisher” with Sherpa-Romeo, a source of information for publishers’ policies on self-archiving and posting papers electronically. Sherpa-Romeo classifies a publisher as “green,” indicating that the publisher permits authors to self-archive their accepted papers on their personal or institution’s website in preprint and postprint…

That’s nice. Here’s a related post about Springer open access on Michael Trick’s OR blog.

MSNBC aired a program about Corporate Social Responsibility this evening. “The Responsibility Revolution” was an installment of the Business of Innovation series. Interesting, if a bit choppy, it airs again at midnight tonight ET, and a number of other dates/times in Europe and Asia. See the schedule.

There is also a green cable channel called planet green.

1. There is a call for papers for a special issue of Operational Research: An International Journal on Optimization Models in Environment and Sustainable Development. Here is an excerpt:

The objective of this special issue of ORIJ is to present recent advances on the ways in which patterns of development can be measured and modelled in the search for sustainability, and also to provide a framework to help decision-makers choose the most appropriate model, on issues like (but not limited to):
- Optimization Models in Environment and Sustainable Development
- Decision Support Systems in Environment and Sustainable Development
- Analysis of the relation between Economic Growth and Environmental Quality
- Optimization Models for Environmental Systems
- Waste Management Planning and Optimization
- Operational Research Applications in Wildlife Management and Ecology
- Optimization Models in Forest and Agricultural Sector
- Evaluation of currently used Optimization Models
- OR Case Studies in the field of Environmental Management
We are particularly interested in new optimization models or improvements in modelling techniques, regarding the environment or sustainable development.

Submission deadline is 31 Oct 2008.

2. The Journal of the Operational Research Society has a call for papers out on an issue about Transportation, Logistics and the Environment. It reads, in part:

There is growing interest in the field of “green” logistics and transportation, which is a domain focusing on environmentally friendly and efficient ways of transportation, both on the passenger front and for freight operations. The special issue aims to put together studies concerning any aspect of logistics and transportation, but with an explicit consideration of environmental factors (such as reduction of energy consumption, air pollutants and greenhouse gas emissions). We are seeking novel, high quality papers that address environmental issues in contexts including, but not limited to,
. city logistics,
. intelligent transportation systems,
. intermodal transportation,
. network design and planning,
. passenger transportation,
. reverse logistics,
. road, rail, air and maritime freight operations,
. supply chain management,
. terminal operations management and planning,
. vehicle routing and scheduling,
Using operational research based modelling approaches (e.g., mathematical modelling, simulation) and solution methodologies (e.g., exact and heuristic solution algorithms). The special issue aims to stimulate interest in green transportation and logistics from the operational research community, capture the state-of-the-art in the domain, and identify potential research directions that will keep the field active in the long run.

Deadline is 30 Sep 2008. See also this post including the comments for related information.

3. The upcoming EJOR issue on Closed-Loop Supply Chains mentioned in an earlier post is actually now a feature cluster of the Dec 2008 issue of that journal. Navigate to this page and scroll to the bottom. It contains an introduction and three papers, one of which (Strategic response to EEE returns: Product eco-design or new recovery processes? by R. Zuidwijk and H. Krikke ) was summarized in a previous post here.

Another talk for the quantitatively-inclined at the recent US Federal Environmental Symposium East was “Results of LEED Building Energy Performance Study” by Brendan Owens of the US Green Building Council (USGBC). LEED is a rating system for buildings in terms of their environmental impact administered by the USGBC. A building can earn points within the system for energy and resource efficiency, use of renewable materials, recycling, diversion of construction waste from landfill, etc.

The talk concerned an interesting study commissioned by the USGBC and completed by the New Building Institute. The key question was how did buildings that received LEED certification when they were completed, perform once they were in operation. 121 certified buildings, representing 22% of the total number, participated in the study. (Note: these were the ones who responded to an invitation, sent to all, to participate in the study, and so do not form a random sample.) The results were that in general, LEED buildings were 25-30% more energy efficient than non-LEED buildings. The data were pretty variable and unpredictable (e.g. some very highly rated buildings performed near the bottom). It seemed like some of the variability could have been mitigated by controlling for building type within the study. Buildings serve different functions. A data center is going to have a different energy use profile than an office building. The results are being used to shape the next version of the LEED rating system. The study is available here.

All told, the symposium showcased many good initiatives and programs. One thing that seemed to be lacking, however, was something along the lines of the cradle-to-cradle viewpoint, with a more critical take on recycling, for instance, and more emphasis on avoiding many of these problems at the outset by more thoughtful design and reuse. There was some evidence of this, as in a different USPS talk about how the amount of hazardous materials they generate has been cut by 90% through green purchasing. But in other cases, recycling programs and green electronics purchases were trumpeted with far less said about reusable over recycled items (such as bottles) and upgrading equipment versus purchasing new environmentally-friendly equipment (like computers). Nevertheless, many steps in the right direction are being taken.

I attended the US Federal Environmental Symposium East in Bethesda, MD last week. This meeting brought together US government agency representatives to discuss programs, plans, analysis, etc. each has been undertaking surrounding sustainability issues. I heard some good talks from members of the Departments of Energy, Agriculture, Defense, and the Environmental Protection Agency, Office of the Federal Environmental Executive (OFEE), National Institutes of Health (the symposium host), and many others. The conference had a strong policy slant; a key focus was how to meet the sustainability goals of Executive Order 13423. (Scroll all the way down for more on E.O. 13423.)

One talk having some good OR/MS content was “U.S. Postal Service Environmental Impact from Reductions in Highway Transportation: Highway Corridor Analytic Program (HCAP)” by Edward (EJ) Matto of IBM and Wayne Corey from the US Postal Service. The talk was about an optimization model geared towards minimizing the cost of the long-haul (think inter-city) postal runs. Previously these trucks were only 60% full on average, so overhauling the routes to produce fuller trucks would lead to fewer runs, hence lower costs. The problem is modeled as a vehicle-routing problem with pickups and deliveries (VRP/PD) using mixed-integer programming. The results have helped save the USPS $5 million annually.

EJ Matto was kind enough to take a number of questions from me after the talk, despite my question about junk mail (see below) during the regular Q & A. One of the interesting (and possibly familiar to some) points he made was that the USPS only implemented a small fraction of the routes suggested by the model. In part this was because doing more would lead to too large of a disruption of the current system. The model results led to incremental changes in the routing, not a wholesale revision of it. Along the same lines, the model starts with existing routes and some potential new ones (generated by heuristics), rather than starting from scratch.

This topic seemed familiar to me, and it turns out a paper on this was published in Interfaces (Pajunas, Matto, Trick, and Zuluaga, “Optimizing Highway Transportation at the United States Postal Service”, Vol 37(6), Nov-Dec 2007). See that for more information about the model. One difference between the paper and the talk was a slide on the environmental benefits of implementation of the results, such as reduced emissions of CO2, NOx, CO, VOCs, PM10 (particulate matters). This registered with the audience. It has probably often been the case that implementation of a good cost-saving OR model has led to environmental side benefits. Fewer miles driven translates to less fuel used, and less pollution. But of course, “efficiency” does not always benefit the environment, especially when environmental capital is not accounted for. Central to the corporate social responsibility movement is the notion of “internalizing the externalities”. The criticism that has often been waged is that pollution, natural resource depletion, and the like traditionally have not been accounted for properly in the cost of doing business. They are treated as externalities. This appears to be changing somewhat nowadays.

As I alluded to above, I asked about the USPS’s view of junk mail given its environmental impact but figuring it was a huge source of income. I received a very lengthy answer from the USPS speaker along with another audience member who also works there. They talked about how the USPS works with direct mailers to reduce the environmental footprint of the “bulk business mail” (that’s the term they use), which makes up 87% of their revenue. They also described a number of sustainability initiatives the USPS is taking on, one of which is cradle-to-cradle certification (see “USPS Goes Cradle to Cradle” at treehugger.com).

Most forms of doing business are going to take a toll on the environment, even ones like the USPS that don’t directly involve manufacturing. It is a problem many companies have to face as they strive to be more environmentally responsible. So what many do is to try to mitigate the impacts of an inherently environmentally deleterious business, and also work hard to be greener in other ways, such as with recycling, alternative fuel vehicles, energy efficiency, etc.

To see more about the efforts of the USPS, go to their greener choices page. (Follow the links on the page to reduce the amount of “bulk business mail” you receive.)

The Center for a New American Dream website has information about a “Do Not Junk” registry patterned after the “Do Not Call” one and also has steps you can take to reduce your own junk mail.

Getting back to Executive Order 13423, from the OFEE site:

On January 24th, 2007, President George W. Bush signed Executive Order 13423, “Strengthening Federal Environmental, Energy, and Transportation Management.” The order sets goals in the areas of energy efficiency, acquisition, renewable energy, toxics reductions, recycling, sustainable buildings, electronics stewardship, fleets, and water conservation.

Some of the goals include:

VEHICLES: Increase purchase of alternative fuel, hybrid, and plug-in hybrid electric vehicles when commercially available.

ENERGY EFFICIENCY: Reduce energy intensity by 3 % annually through 2015 or by 30% by 2015.

GREENHOUSE GASES: By reducing energy intensity by 3% annually or 30% by 2015, reduce greenhouse gas emissions.

(src: E.O. 13423 Fact Sheet (pdf))

Update: A June 25 Washington Post story discusses US Presidential candidates’ energy/environment plans and also refers to EO 13423.

According to a nice, brief piece by Heiner Müller-Merbach in Omega entitled “The Interdisciplinary Generalist”, being interdisciplinary is an “old” but “often forgotten” virtue of OR/MS. He writes:

The rationality behind the necessity of an interdisciplinary approach to problems is simply that problems in general are not ordered according to the scientific disciplines; instead, most real problems (at least the major and more complex ones) have at the same time physical, chemical, technical, economic, legal, social, ethical aspects etc.

Somewhat obvious, and somewhat generalizable beyond OR/MS, but at the same time, it seems, somewhat understated within the field, especially at a time when interdisciplinary institutes are continually forming. (Google “interdisciplinary institute” to get a sense. In the sustainability realm, see the article “A Threat So Big, Academics Try Collaboration,” NY Times, 12/25/07, probably worth a post of its own.)

Müller-Merbach goes on to describe the content, abilities, and feel, from various disciplines, such as mathematics, science, engineering, fine art, social science, etc., that an interdisciplinary generalist should aspire to obtain.

This factored into an undergraduate project I advised this past semester on analyzing waste flow at the US Coast Guard Academy. Some disciplines, and the content within, that were important for the project group members to handle included:

• policy - government programs and regulations regarding the disposal of waste
• business - contracts, organizational structure (of offices responsible for waste), labor
• math - model formulation, multi-objective linear optimization, multi-criteria decision analysis
• science/engineering - workings of waste flow alternatives such as a trash compactor, organic waste composting
• ethics - environmental objectives and constraints, hazardous waste
• economic - purchasing, contracts (again), cost minimization
• sociological/psychological - changing attitudes/behaviors surrounding waste and purchasing, implementing new responsibilities among groups and individuals, education about waste flow alternatives
• technical/computer - spreadsheet optimization, database programming

It was a nice reminder for all involved, that it is not just about the math. (More on this project later…)

Corn-ethanol bio-fuel is another example calling for an interdisciplinary approach. There is debate about whether it makes sense to pursue it. Here are some questions surrounding the issue, followed by the disciplines one would need to help answer them:

1. What is the impact on food supplies, prices and beyond, of switching corn production from food to ethanol?
   Economics, Agriculture
2. Is the energy balance favorable for ethanol, i.e. does corn ethanol contain more energy than it takes to produce it?
   Thermodynamics, Agriculture
3. Are government incentives working properly?
   Policy/Regulation, Economics, Marketing

Granted, some of these can go beyond the purview of OR/MS, but the majority lie within.

[For one take on #2, see Thermodynamics of the Corn-Ethanol Biofuel Cycle (pdf) by T. W. Patzek.

"The Ethanol Myth" in the October 2006 issue of Consumer Reports also mentions #2. In addition, it hits on #3 with a good discussion about the impact of flexible-fuel vehicle (FFV) credits.]

OR50
This is the 50th anniversary conference of the UK-based OR society. It is being held in York, England from September 9 - 11, 2008. Plans include a plenary debate on sustainability and OR within the conference’s “Agriculture and Natural Resources” stream. That stream is being coordinated by Daniel Sandars and Lluis Pla, both mentioned elsewhere on this site in conjunction with EURO 2007. I have supplied some points to this debate effort. For more information, see the “operational research for the natural resource industries” blog.
Update: The program for or50 (pdf) has been posted.



INFORMS 2008
The April 2008 issue of ORMS Today included a list of 21st century engineering challenges to which OR could contribute. The list included developing a self-sufficient sustainable energy program. (Some of the other entries were improving healthcare in developing countries and in the United States; developing effective counter-terrorism strategies; and using the Internet to improve education in emerging countries. See the article for the complete list.) The report the list is based on, authored by current and former INFORMS presidents, talks about how OR is well suited to handle the sustainable energy challenge, because of its experience with networks, and analysis of trade-offs, to put it briefly. The ORMS Today piece goes on to mention plans for sessions at the 2008 INFORMS meeting, focusing on these challenges.

Note, the following are among the possible subjects to classify one’s abstract submission to the conference: sustainable operations; environment, natural resources and energy; sustainable development; and green design/buildings. The INFORMS meeting will be in Washington, DC from October 12-15, 2008.

A number of articles discuss environmental issues in operations management. Here are a few:

Environmental and Operations Management Face the Future
L.C. Angell
in Decision Line, May 1999
Notes: This brief article from 1999 includes a table listing special journal issues on environmental operations management and related areas. I am listing these and some others I have found in a separate post.

Integrating environmental issues into the mainstream: an agenda for research in operations management
L.C. Angell and R.D. Klassen
in Journal of Operations Management, Volume 17, Issue 5, August 1999, Pages 575-598
Notes: Same author as above. For what it’s worth, Scholar reports 165 citations as of May 5, 2008. If nothing else, given that these references are a bit old, mine the citing papers to find more recent work.

‘Green’ value chain practices in the furniture industry
R. B. Handfield, S. V. Waltonb, L. K. Seegersc and S. A. Melnyka
in Journal of Operations Management, Volume 15, Issue 4, November 1997, Pages 293-315

Environmental operations management: An opportunity for improvement
M. Gupta and K. Sharma
in Production and Inventory Management Journal, Volume 37, 1996

The sustainability debate
A. Wilkinson, M. Hill, and P. Gollan
in International Journal of Operations & Production Management, 2001, Vol. 21, Issue 12, 1492 – 1502

See also the post on special journal issues.