Category: IFORS

IFORS Distinguished Lecturer

I am at the closing session of EURO. This year’s conference was huge with more than 2000 participants. I did attend a good amount of the conference, though Prague has its own attractions.

EURO (along with INFORMS, ALIO, and APORS) have a plenary given by the IFORS Distinguished Lecturer (I chair the committee that recommends the selection to the President of IFORS). This conference’s IDL is Bob Bixby, from Rice University and ILOG. Elise del Rosario introduced Bob, and here are some quotes from her introduction:

The IFORS Distinguished Lecturer for this conference is
Dr. Robert Bixby, an outstanding researcher, innovator, and business
leader. Dr. Bixby received his Ph.D. in the early 1970s from Cornell
University, and looked like he would have a long and distinguished
career in research on combinatorial structures. A sharp turn in the
1980s led him to develop CPLEX, an outstanding large-scale linear
program optimizer. CPLEX led to CPLEX Optimization, Inc, marketing
algorithms for linear and mixed-integer programming. CPLEX was sold
to ILOG in 1997, a company in which Dr. Bixby has served a number of
roles and where he is currently Chief Science Officer.

Dr. Bixby has combined his business success with continued research
success. He, along with his colleagues David Applegate, Vasek
Chvatal, and Bill Cook have just published a book entitled “The
Traveling Salesman Problem: A computational study” that sum up their
20 years of work on solving large scale traveling salesman problems,
culminating the solution of TSPs with tens of thousands of cities.

Dr. Bixby has held a number of leadership roles in our field,
including the presidency of the Mathematical Programming Society, and
has received a number of awards for this work, including the
Beale-Orchard-Hays Prize for excellence in computational mathematical
programming.

The title of his presentation was “From Planning to Operations: the Devil’s in the Details”.  Unfortunately, I had to run out for a plane (for my 42 hour return to New Zealand) so I only got to see the first part, where he reviewed progress in linear programming and integer programming.  A few striking points:

  1. The speed improvement in linear programming from 1996-2004 is a factor of about 5.3 million (3600 due to algorithms and 1300 due to computing).
  2. Not much improvement in linear programming the last few years:  only computer speed improvements.
  3. (Mixed) integer programming is about 13 times fast over the same period.
  4. The next version of CPLEX provides another decrease in time required (by a factor of .6)
  5. The next version of CPLEX is much better at finding feasible solutions to MIP (a test set of about 1300 instances) went from 250 with no solution found in 100 seconds in CPLEX 10 to about 120 in the next version.

The main point of the rest of the talk is that MIP and other optimization models are going to be used increasingly for day-to-day decisions (not as an aid to decision making, but making the decisions directly) and that puts lots of pressure on our models and data.

On my way to Prague

I’m in the Hong Kong airport on the way from Auckland to Prague. I have about 22 more hours to go before I arrive at my hotel. It is great spending a year in New Zealand, but it is definitely a long way from anywhere!

Hong Kong airport is beautiful and incredibly well organized. I compare this to the alternative routing through Los Angeles, and there is absolutely no comparison. LAX is chaotic, rude, and very difficult (in my admittedly limited experience). Here, transferring flights involved no formalities at all: just a quick security check and into the departure areas, absolutely full of shopping, lounges, bars and restaurants.

I am on my way to the EURO conference. It is too bad this conference conflicts with the INFORMS “International” in Puerto Rico. Both are conferences I would like to attend. But the IFORS executive is meeting in Prague, so that is where I am going. I’ll try to provide an update or two along the way.

Looking for an Editor

ITORInternational Transactions of Operational Research is looking its next editor. I chair the search committee. We just did a review of the journal, and I think it offers an interesting opportunity to the right person. The key is trying to make the journal not just a “me-too” journal, taking the rejects from higher-ranked journals. The issue is finding the right niche. Since the journal is sponsored by IFORS, making the journal a key outlet for “international operations research” seems a very promising direction.

But what is “international operations research”? Lots of OR seems country/culture-independent. Certainly much of “mathematical programming”-type operations research does not seem “international” in any way. But there are issues of particular interest to developing countries that seem quite international. And there are many topics in international management that seem to fit (models in international operations for instance).

I guess I am hoping that someone out there will come up with a convincing vision of what “International OR” could be and how ITOR could play an important role in achieving that vision.

IFORS feels strongly about wanting the journal to succeed. The Administrative Committee has budgeted some funds for the activities that generate journal material (workshops, datasets, etc.) to help make the journal a success.

Here is the full call for nominations:

Continue reading “Looking for an Editor”

Off to Iceland!

Iceland GeyserI leave tomorrow for Iceland for the EURO 2006 conference. Busy time: in addition to the IFORS Administrative Committee Meeting, I am giving a semi-plenary on “The Society of Operations Research” (more on social capital and OR) and introducing Saul Gass as the IFORS Distinguished Lecturer.

They expect more than 1700 participants at this conference, almost triple their initial expectations of 600. This has been a huge issue for the organizers since it is a busy period in Reykjavik and there are only about 3000 rooms in the city. They have done an amazing job!

Since INFORMS Pittsburgh is also looking larger than expected (with more than 3200 abstracts submitted) it is clear there is quite a bit of enthusiasm for conferences. I am not sure why that is… perhaps the economy is better so people have more travel funds.

I’ll try to post some thoughts from the conference, along with some Reykjavik pictures.

Luk Van Wassenhove and IFORS Distinguished Lecturer

Luk Van Wassenhove was the IFORS Distinguished Lecturer at this year’s INFORMS conference. Here he is receiving congratulations from Tom Magnanti (right), President of IFORS.

Luk spoke on “Closed Loop Supply Chains: Past, Present, and Future”. Closed-loop supply chains are those where the supply chain bringing goods from consumers back to suppliers is also important. Luk gave an interesting historical perspective on this rather young field. He suggested that the field has gone through 5 phases:

1) Technical remanufacturing. Research into how to best remanufacture/resuse returned items, with little regard to how they come back or where they go after remanufacturing.

2) Valuing reverse logistics. Research and interest in how items coming back to a supplier can create value for that supplier. These models are more market driven than just waste stream recovery, and address the front end acquisition of items.

3) Coordinating decisions, bringing the forward supply chain together with the reverse supply chain. Once the magnitude of the problem is realized, the reverse chain impacts the forward chain, and vice versa.

4) Closing the loop, with dynamic decisions over the lifecycle of products. One aspect of this is the need to spend money to make money. Consider a “recycled” computer: one that is only a few weeks old is much more valuable than one that is months old. In such a case, investments might need to be made to increase the speed of the reverse supply chain.

5) The final phase of research, which perhaps should have been the first one, is “Is there a market”? While this area has increased in academic stature, and there are visible, but isolated, examples in practice, how can these insights be embedded in real firms. This brings in issues of accounting (how should returns be valued) and marketing (how should cannibalism be handled between original and remanufactured products)?

This was an ideal plenary session: broad, understandable and interesting.

OR in Africa

There have been a couple of things I have seen recently highlighting OR in Africa. The first was a presentation by Luk Van Wassenhove on humanitarian logistics (here is an article Luk, David Kaatrud and Ramina Samii wrote about the UN Logistics Centre). While not limited to Africa, that region is certainly a key area. Humanitarian logistics offers a tremendous mix of organizational and technical challenges, not the least of which is coping with the sheer number of governments, NGOs, and other organizations, all with different objectives and requirements.

An article in the October OR/MS Today by Jonathan P. Caulkins, Emily Eelman, Minoli Ratnatunga and David Schaarsmith talked about a conference in Africa, the Operations Research Practice in Africa conference. Held in Ouagadougou, Burkina Faso, this conference looked at opportunities for real-world problem solving using OR to address Africa’s issues. The summary brings up some interesting ethical issues (should OR be used to help repressive regimes?) and some area-specific OR issues (particularly the non-routine, non-replicable nature of crisis handling).

IFORS is holding its 2008 international conference in Africa: Sandton, South Africa to be specific. I’m traveling there in February to check out sites and speak with the local organizers. It turns out to be easier to get there than I thought, with direct (one stop for fueling) flights from JFK, Dulles, and Atlanta. I am also going to spend a few days in Capetown.

The issues brought up in these papers do make me wonder if working at scheduling professional sports leagues (my own current research) is the most valuable thing I can do with my life!