Tuesday, 13 January 2009

O.R. in Eritrea


When IAOR prints an abstract relating to O.R. in a developing country, it is usually cross-indexed with the name of that country. So the latest "OR in a DC" abstract marks a rare event -- it is the first that has been included (as far as my records go) about O.R. in Eritrea.

The paper is:
Cost analysis of an integrated disease surveillance and response system: case of Burkina Faso, Eritrea, and Mali
by
Zana C Somda, Martin I Meltzerl, Helen N Perryl, Nancy E Messonnier, Usman Abdulmumini, Goitom Mebrahtu, Massambou Sacko, Kandioura Toure, Salimnta Ouedraogo Ki, Tuoyo Okorosobo, Wondimagegnehu Alemu and Idrissa Sow
published in:
Cost Effectiveness and Resource Allocation 2009, 7:1doi:10.1186/1478-7547-7-1

Papers with so many authors/co-authors are also rare events.

By the way, if you don't know where Eritrea is, the map shows it in the north-east corner of Africa, bordering on the Red Sea.

Wednesday, 7 January 2009

Innumeracy

There is currently an advert on UK commercial radio which trades on people's innumeracy.
Switch from sugar to a sugar substitute and "you will save about 7000 Calories per year".
It sounds a lot, but that is les sthan 20 per day, i.e. less than 1% of the daily recommended intake.
But "Seven thousand" sounds a lot, doesn't it!

Think of the user!

Good O.R. has to be implemented. Period. Full stop.
So, at some stage, someone needs to think of the person who will use the results. The problem may have been presented by management, and the person who pays for the work is in the management hierarchy, but the person who actually uses the results is probably not in management. Which is why implementation is important.
I have linked implementation and design before, but over the Christmas holiday we had experience of both good design (implementation) and bad.
Let's start with the bad news. We bought a new set of Christmas lights to make an arch around the front door. They came with an integral control box which had one button only. Repeated pressing of the button cycled through several patterns of flashing lights, with one where all bulbs stayed on all the time. So we put the string of lights up, switched on and discovered that the default was a pattern which faded and flashed -- too garish for us. So we cycled and selected the constant selection. Then we switched off, to put the string onto a time switch. When it came on, we were back to the default. As a result, at some stage every evening, yours truly had to press the button to select our favoured setting. With a little forethought, the designer could have ensured that the setting that had been selected became the default one for the next off--on sequence ... because that is what the user had expressed a wish to show what was wanted.
The good news was that Tina was given a DAB radio. Plug it in, switch it on, and set up the controls. It was extremely easy, with clear instructions, designed with the user in mind. Full marks for those at "Pure" for thinking of the user.

Monday, 5 January 2009

O.R. and waste management2

Another slant on a topic which I referred to in August 2008
One of the responsibilities of editing the International Abstracts in Operations Research is to have an awareness of the areas of application of O.R., and especially those which lead to publications in the academic literature. Someone has said that applications of O.R. should be so good that they can be published in the literature of the application area. And that imposes a high standard for the O.R. scientist, having an ability to work within another discipline to such a high standard that ones work stands up against the peers in that discipline.

So it is interesting to notice that more and more O.R. work is being reported relating to waste management. An IAOR search in the online version produced over 240 hits for "waste AND management", running across many aspects of the subject: location of facilities, vehicle routing and scheduling, capacity planning, multicriteria models for planning a waste management programme, etc. etc.

But comparatively little of this work has appeared in the O.R. literature. It is mostly in the application area. I wonder why?

Monday, 15 December 2008

The British Post Office

At the end of last week, many news bulletins in the UK carried a story that British Postal Delivery workers ("Postmen" or "Postwomen") were unhappy with a new computer system which had changed their delivery routes. According to the stories, some postpersons were having to walk at 4mph for three and a half hours. (Example story.)

The stories were short on detail about the "computer system" except that it had details of 27 million addresses and came from Canada with the name of Pegasus Europe. It seems to have been around for several years, but evidently there have been recent changes in the system which have led to the unhappiness.

Reading the story, it was obvious that there was a mathematical model behind Pegasus of a familiar kind -- optimal (or efficient) route planning for vehicles (postpersons) with constraints (loads, time). Someone, somewhere had been using operational research to help the postal service. And as an operational researcher, I ought to feel proud.

But I don't. The news reports showed that something was lacking in the O.R. process. I can recognise several possibilities for what was wrong, but without further information I can't give a full diagnosis. Maybe someone from the post office can help. So, in no particular order, here are my observations and questions:

(1) Was this system tested and developed for the UK postal service, or was it an off-the-shelf system into which British data was inserted? If it was the latter, then did anyone verify the assumptions that had been made by the designers?
(2) Given the size of the database, it seems likely that the system is largely, if not wholly, deterministic. If so, what sensitivity analysis was carried out? And if so, what changes were made to the data and the model as a result? If not, why not?
(3) How much communication was there before, during and after the development of the system? Who with? Did the creators/users of the system discuss what they were doing with staff at all levels of the system?
(4) Was the objective simply cost-based? Or were there other criteria?
(5) Did anyone concerned with the data collection, input, modelling and recommendations actually go out and test the results? Or, to put it bluntly, would the modeller trust the model's output if they were asked to do a postperson's job?
(6) Did the modellers collect feedback from the postal service about the implementation?

For years, I have taught that an essential part of O.R. is a feedback loop, that an O.R. project is not properly implemented until it has been accepted (and possibly welcomed) into the practice of the organisation. It seems, from the press, that this project lacked this.

We are often reminded of places in companies where there is "OR inside". I feel that this is a story of "OR Inside" which omitted the essential, friendly face of OR outside.

Where was Genchi Genbutsu?

eBay and the AHP

I am an eBayer (or whatever the appropriate term is) to buy items for my stamp and postal history collection. From time to time, I have also sold on eBay. As such, one becomes aware of the size and complexity of the organisation that hs come to symbolise online trading in many countries. From time to time, once one has registered with eBay, one becomes aware of the data analysis carried out by the company's statisticians. I was emailed to ask if there was anything wrong, as I had not bought as much in the previous few months as I had in a similar period earlier -- in other words, my behaviour was outside their forecast limits.

Last week, I was invited to take part in an eBay survey and said yes. I am not sure what behaviour of mine had prompted this particular survey; it may have been another action that was outside their forecast limits, when I bought in a "Buy it now" sale; I invariably use auctions for my collecting.

There was something familiar about the structure of the questions, but I confess that I didn't recognise what it was until after I had answered the last questions and submitted the online survey. eBay was using the AHP (Analytic Hierarchy Process) to find out what I felt about some of the factors that vary from vendor to vendor. I was asked to imagine that I was considering an item at a particular price (30 British pounds) in a Buy it Now sale. That fixed one variable. Then I was asked to consider variations of delivery cost, photo and description quality, speed of communication, first in a ranking, and then by a succession of "Which do you prefer?" comparisons where two sales with differing profiles were offered. I think that I was reasonably consistent in my answers, although the example sales that were offered did not fit into my profile of eBay use. (For stamps, postage is seldom more than GBP1 within the UK and usually less than USD3 internationally; the examples offered had postage figures of up to GBP6.)

Wanting to find out more, I Googled for "eBay analytic hierarchy process" and came up with the answer that eBay does use AHP and ANP (network) and its use is mentioned in the citation of an INFORMS award to Thomas Saaty and in a publicity release put out by Decision Lens, the consultancy used by eBay for their AHP work.

It is strange to contribute to an OR study and only realise that you are doing so afterwards!

Monday, 1 December 2008

Genchi Genbutsu

Genchi Genbutsu is a new expression for me. It was posted in a discussion board, as relevant experience for anyone in O.R.. The wikipedia summary is:
Genchi Genbutsu (現地現物) means "go and see for yourself" and it is an integral part of the Toyota Production System. It refers to the fact that any information about a process will be simplified and abstracted from its context when reported. This has often been one of the key reasons why solutions designed away from the process seem inappropriate.

I don't know why there is so little literature drawing on the parallels between Genchi Genbutsu and practical O.R.; good O.R. requires the modeller to understand what is happening in practice, and you do not learn that by sitting in an office. I suppose that there are eqivalent expressions in English -- "go and see for yourself", "management by walking around", "walk the line". But too many managers (and a few O.R. people) rely on second-hand information.