Tuesday, 16 September 2008

Operational Research and Psychology

Well, actually, as many people have pointed out in the past, psychology is part of O.R., so my title creates a false split.

A part of my education in O.R. was the apocryphal story about the O.R. consultants and the problem of the lifts in the skyscraper. Occupants of the building complained about the time they spent waiting for the lifts to get from the upper floors to the lobby. So the consultants looked at the options, they built models of the consequences of extra lifts, faster lifts, dedicated lifts from the upper floors, etc., etc. The reduction in mean waiting time was always very small. Then the psychologist in the team suggested that the company place mirrors in the waiting areas for each lift shaft. He explained why. Why? (see the end of this blog)

I had the same sort of problem at the weekend. Each year, on the second Saturday in September, I take part in a prayer walk around the churches of the city of Exeter, my home. The idea is that a group will start early in the morning, follow a winding route around the city, stopping to pray in about 25 different churches, praying for the city and its people. I have the responsibility of planning the route; for several years we have used the same route. This is not a TSP, of course, because the walkers don't end at the start point. It is not quite minimal but is quite close to the best.

In 2008, two new churches came into the list of city churches. We decided to include one of them, miss the other, and omit another, because it was linked strongly with these two. But the selected new church would add so much extra mileage to the old route that we needed a new plan. So we made the walk have two starts, with two groups starting at 8am and converging on the cathedral at 10am to walk for the rest of the day together. So I devised such a route; the two initial legs had minimal lengths for the churches that they visited, given the fixed end at 10am. However, I had forgotten the psychology. The second route had a lot of road walking, and went past the main railway station, so there was traffic. The consensus was that it would be better to walk a little further (about 300 to 400 metres) and walk beside the river on a footpath, away from the traffic. So that is what we will probably do next year -- alter the start and route to give more traffic-free paths.

Why the mirrors? The reason was that it was not the actual waiting time that people notices, but the perceived waste of time. Mirrors distracted people; some could admire themselves and tidy their clothes and appearance, others could watch. (In the 1970's there were sexist stereotypes for these activities, which I will not repeat.)

Wednesday, 10 September 2008

Education and brains

"To repeat what others have said, requires education; to challenge it, requires brains."

Mary Pettibone Poole, A Glass Eye at a Keyhole, 1938

I had not come across this thought-provoking quotation until yesterday; then I was in a meeting and found it inscribed on the wall of the small conference room. Yes, it has O.R. applications. Part of the skill in the O.R. scientist should be (must be?) the ability to recognise where a model developed earlier in a different context might apply to a practical problem. So queue theory is used for call centres and for slow moving inventories. Location theory applies to ATM outlets and airports. But sometimes the obvious is not appropriate -- then the O.R. scientist needs brains to challenge the obvious.

Wikipedia doesn't tell me anything about the author or the book. And I wonder who has used their brains and challenged Mary's words, rather than repeat them?

Operational Research and Christianity

I recently read that the educational background of the Bishop Sarah Frances Davis in the African Methodist Episcopal church has a degree in Management Science. Can O.R./M.S. help in such a role? In IAOR, there are several papers recorded which refer to applications of O.R. in the life of the church. In the 1970's and 80's, Malcolm King, Alan Mercer and I published some papers about the place of modelling in the deployment of clergy in the U.K.

[Malcolm King, David K. Smith and Alan Mercer "Towards Diocesan Planning" Journal of the Operational Research Society 29 p856-866 (1978); Malcolm King and David K. Smith "Are the Clergy Being Deployed Fairly?" The Churchman 5 p54-60 (1980); Malcolm King and David K. Smith "Planning the Deployment of Clergy" Long Range Planning 5 p104-111 (1982)]

Earlier, Alan had published "The Churching of Urban England" in the proceedings of the 1969 IFORS conference, which looked at the location of places of worship.

So there are two possible areas for fruitful O.R.; manpower planning, and location models.

I wonder if Bishop Davis knows about this work.

Monday, 1 September 2008

The Numerati by Stephen Baker

Also in the INFORMS enews:

Business Week
reporter Stephen Baker, has written The Numerati, which describes the superpowered contributions that mathematicians-and operations researchers-are making to businesses and organizations today. Publishers Weekly has given advance praise, calling The Numerati a "captivating exploration" about "a new breed of entrepreneurial mathematicians." Houghton Mifflin is publishing the book this fall (autumn if you live in the United Kingdom).

There is a video of an interview with the author here.

Blogging on O.R.

In the INFORMS enews, there was this note:

Some of INFORMS' most enthusiastic members are blogging about O.R., operations management, engineering, and science. Have you visited their blogs yet?

Former INFORMS President Michael Trick of Carnegie Mellon University, who currently serves on the INFORMS Public Information Committee (PIC), blogs from conferences and shares fresh news about O.R. Michael Trick's Operations Research Blog.

Fellow PIC member Aurélie Thiele of Lehigh University shares her views at Thoughts on Business, Engineering, and Higher Education.

Wharton Professor Gerard Cachon, the current editor of M&SOM and the incoming editor of Management Science, blogs on operations management at Matching Supply with Demand.

Visit these blogs, catch up on news and views, and share your own O.R. perspectives. Know about more O.R. blogs? Let us know by sending an email to barry.list@informs.org.

To which we can add this blog, and that of Laura McLay
(Punk Rock Operations Research)

Swimming again

A footnote to the blog (10th June 2008) about modelling demand for swimming.

A major cereal company in the U.K. (the name begins with "K") offered vouchers for free swims on its packets. As a promotion, it has been very successful. But the swimming pool in Exeter has had to restrict the hours when the vouchers can be used. It isn't really a rationing of use, simply a way of allowing the fee-paying swimmers time to enjoy their swim and concentrating the use of the vouchers to times when fee-payers can stay away.

This is an interesting solution to a demand problem. It has obvious links to revenue management.

My week in O.R. at the IFORS 2008 conference

The newsletter of the U.K. O.R. Society includes a feature "My week in O.R." or "My month in O.R.". In the issue for September 2008, my contribution about the IFORS conference was included, as follows:

It’s 9:20am on Sunday morning, and I’m going into church. Together with my wife Tina I am in Sandton, South Africa for the triennial IFORS (International Federation of OR Societies) conference, which starts today. Sandton is a strange place – a suburb of Johannesburg – with a strange, artificial air to it. We arrived yesterday and checked into one of the conference hotels. It’s four-star, international, impersonal and totally devoid of character. We are noticing the difference (it is almost culture shock) after a week and a half of holiday. The first week was a safari in an overland truck, staying in game lodges and backpackers’ hostels, in a group from five countries and speaking three languages. The beds were more comfortable than our four-star accommodation here, and the staff of lodges and hostels were friendlier.

Amidst the hotels, offices and shopping malls of Sandton, there is one convenient church; I’ve tried to find somewhere to worship at most of the IFORS conferences that I have been to, with interesting results. Here Tina and I, with conference friends, have arrived to find the church empty except for one man fixing the P.A. “Everyone else will be along shortly” he tells us; sure enough, at 9:28, the church fills up ready for the 9:30 service. We are welcomed, and the service proceeds, with more and more people drifting in over the next half-hour. The sermon – longer than in most U.K. churches, has an O.R. link; some of the New Testament parables stop with a cliff-hanger and seem incomplete; isn’t this a bit like some reports of O.R. work, which leave the reader asking “What happened next?”

My afternoon is spent talking about the International Abstracts in O.R. (IAOR), which I edit, and whose sales provide IFORS with a steady income stream. The conference is the time when we are launching an updated version of the electronic IAOR, so the leaders of IFORS are particularly interested in the report. Then I get involved with a meeting for editorial advisers of another journal, which is filled with statistics about submission rates and publication delays.

IFORS conferences follow a regular pattern: reception on Sunday, two days of papers, one day-long excursion or choice of excursions, and two more days of papers. The evening’s reception has been scheduled for two and a half hours, and by the time Tina and I get there, people are already drifting away. O.R. observation: receptions should be shorter, to allow people to meet one another; what is the optimum length?

Being in Africa, the conference opens with drumming and dancing, followed by a welcome from the minister of science and a plenary speech by Clem Sunter about Scenario Planning “The world and South Africa in the 2010s”. Some of his remarks about planning are clearly particularly pertinent for the minister. Then there are the usual parallel sessions that make up all conferences. I opt for the session on developing countries, to hear the seven papers that have been shortlisted as candidates for an IFORS prize. Like many conference sessions, this one is a curate’s egg.

I skipped out of the sessions for part of Tuesday to accompany my “accompanying person” on the trip to a glass factory – which was ninety percent disastrous. The most interesting bit was meeting the team who had created the key-rings in the conference packs. Made of glass beads, threaded onto wire, each is different. Our guide explained how the random patterns were produced, using a device worthy of Heath Robinson; all the parts used are recycled materials. The following day we have opted for a trip to a diamond mine. What struck us most forcefully was the ordinariness of the site, apart from the intense security. We didn’t lose touch with O.R.; the mine has monthly performance targets, derived from a forecasting model. Earlier this year, the target was missed because of power cuts; loss of 20% of the power meant a loss of 50% in production.

Sandton is a strange place for a conference. Because of the security, Tina can’t simply go off for a walk, and she spends a good deal of time reading in the hotel garden. There is a wide choice of shopping malls, one linked to our hotel by an underground passage, another attached to the convention centre. Even the winter sales in the shops fail to attract her for very long.

Thursday – another day of parallel sessions. In the evening, the gala conference dinner, enlivened (if that is the right word) by a parade of representatives of the 48 national societies that are members of IFORS, ordered according to when each society joined the federation. There is more dancing, loud jazz music, queues for the buffet, and very few speeches. Years ago, I read some words of Hermann Bondi: “Little children, from the age of three upwards, ask the question ‘Why?’ The aim of education is to stop such questions. Education has its failures. They are called scientists.” The dinner is a time for me to ask “Why?” and the subsequent question, for me (as an O.R. scientist), is “How?” “Why is the service so poor? How could it be improved?” These two questions have never been far from my mind all week. “Why is the design of the convention centre where the conference is being held so weird and inefficient? How …?” “Why is the hotel service indifferent? How …?” My mentors in my distant O.R. youth emphasised the importance of time spent on site, experiencing the problem that was being studied; managers in service industries often should learn the same way, experiencing the service as a customer and seeing how it could be improved. The hotel has a sort of feedback loop of control, with customer response forms; will any of my comments be dealt with if I were to come back next year?

And then comes Friday, and the closing plenary session. Very interesting, but the presentation is very poor, and the speaker could have said in 20 minutes what took 45. Those delegates who are still around start to disperse, some back home, others to holiday in South Africa. Has it been a successful conference? Yes, I have met a lot of people, some old friends, some new ones. Have there been any outstanding sessions? Not for me, sadly.

Back in the office in Exeter the following Monday, there are my emails to be dealt with, and a meeting with my research student, M, and her project sponsors. She has been trying to make sense of a large mass of historic data; we spend time trying to get something useful out of it for the sponsor. I encourage M to “play with the data” to try and find useful information, though I remind her that this is not an expression to use in our presentations. The meeting with sponsor goes well, as we are joined by one of the U.K.’s experts in the type of data we are looking at, and he has excellent communication skills as he talks about the project and its context. He doesn’t mind when I ask those two questions, over and over “Why?” and “How?”. In terms of information gained, the hour with him has given me as much as the whole conference.