Ailsa H. Land

Brief Biography

Ailsa H. Land (née Dicken) was born in West Bromwich, Staffordshire, England to Harold Horton Dicken and Elizabeth Grieg. Her parents  She lived as an only child with her parents in various semi-rural areas between Birmingham and Litchfield, attending local day schools until 1938. Then at the age of eleven she joined a small mixed prep boarding school on the clifftops at Hastings. For the first time Ailsa began to enjoy school.

By early 1939 Ailsa’s parents foresaw the approach of War. To investigate the possibility of the family’s emigration to Canada, her mother, accompanied by Ailsa, embarked in April on a “holiday visit” to her relatives in Canada. By September 3^rd, Britain and Canada were at war with Germany, and mother and daughter were apparently trapped in Canada for the “Duration”. Harold Dicken remained in England and served as a Catering Officer in RAF Bomber Command stations until the end of the War in Europe, May 1945.

Ailsa attended three more school in Canada, and finally settled at her seventh school in 1940 at the Malvern Collegiate Institute in Toronto.

By 1943 Canada was sending troops to Britain, including female members of the forces. Ailsa and her mother decided to join the Canadian Women’s Army Corps (CWAC) as their contribution to the war effort and as a possibility of reaching home within that organisation. Ailsa adjusted her age from 16 to 18 in order to join the CWAC.

After serving separately in various cities in Canada, by late summer 1944 both Ailsa and her mother were stationed in Ottawa in a National Defence Headquarters office, run entirely by female staff replacing male soldiers who had been dispatched to join the troops in England preparing for the invasion of Nazi-occupied France. Suddenly they had news that Harold Dicken's life was in danger due to a forthcoming operation. CWAC awarded a compassionate demobilization to both, and after a hectic few days they began a 10 day Atlantic crossing in a small freight ship in what was probably the last 50-ship Atlantic convoy of the war. (The submarine threat was almost over.) By the time they reached England, Harold Dicken was recuperating.

While the War continued until VE Day (May 8^th, 1945), Ailsa Dicken was fully occupied with family concerns as well as trying to qualify for University entrance. Lacking any particular career plan, she was attracted to the London School of Economics (LSE), which offered a broad range of subjects from which to select after the first year of study. She had a grant from her service in the CWAC which was enough to start on, and she expected to be able to use her skills in typing and shorthand to supplement the remaining funding for a first degree. Ninety percent of university places in the immediate post-war period were reserved for ex-service personnel as demobilization followed the end of the war in Europe, so she was accepted as a first-year student for the BSc (Econ) in 1946 at the age of 19.

Her first-year exam paper results were very mixed, but evidently she was judged sufficiently competent in the Economics paper to warrant an award (Bowley Prize) and she decided to make that her Special subject. Taking a good degree in 1950, she was offered a Research Assistantship in the Economics Research Division at LSE. This was at the time largely seen as a training ground for eventual university faculty in order to build up the depleted British universities.

Other 1950 graduates in the Economics Research Division included Frank Land (and his twin brother). In time, this led to the marriage in 1953 of Ailsa to Frank Land. By that time she had become interested in Activity Analysis (Linear Programming) and had decided to pursue an academic career, explicitly recognizing that trying to combine that with family life might cost a large part of an academic salary. She had not yet published under the name Dicken and therefore accepted the (rather old fashioned) practice of changing her surname to Land as being easier for prospective children. Eventually she began to live a “five-two” life – weekdays for career, weekends for family life. She was lucky (almost all the time) in the women who acted to fill the weekday gaps. (One actually stayed with them for nine years, and even now comes to visit their great-grandchildren.)

She progressed through the ranks of research assistant, lecturer, senior lecturer, reader, and then chaired professor. Her economics background and perspective informed her subsequent contributions to OR, beginning with her 1956 dissertation on the application of OR techniques to the transportation of coking coal and extending to publications on a wide variety of applied problems (including international trade, manufacturing layout, machine scheduling, and sports analytics). Note that these applied problems were discovered in published papers, not in general contracted for development and use.

Ailsa is especially well known for her development, along with Alison Doig, of what later came to be called the branch-and-bound method for optimization problems with integer variables. Their groundbreaking 1960 work, published in Econometrica, has since been extensively cited and applied by the mathematical programming community. Indeed, most serious implementations of OR optimization software include branch-and bound routines. Interestingly, the work of Land and Doig was carried out at the LSE under the sponsorship of British Petroleum, in order to enhance existing linear programming models for refinery operations in which some variables were necessarily integral. This instance differs in that it was contracted work and it paid the Research Division a year’s salary for Ailsa Land and Alison Harcourt (née Doig) to try to develop an optimizing routine for integer LP problems, being aware that they did not have access to a computer, but would develop an algorithm that would be easy to convert to Fortran by BP’s own staff. The company did not wish to publicize the existence of this contract with LSE.

She also conducted early investigations of the traveling salesman problem, beginning with a 1955 paper with George Morton, and continuing with a 1979 research report on 100 city traveling salesman problems. This latter work applied cutting planes and a heuristic for subtour elimination constraints to obtain considerable improvement on previous approaches. In addition, Ailsa advanced OR methodology through publication of notable work on shortest path algorithms, quadratic programming, bicriteria decision problems, and statistical data fitting. Since retirement from the LSE in 1987, she has continued several research projects, resulting in contributions to data envelopment analysis, the quadratic assignment problem, and combinatorial auctions.

It is significant that Ailsa was not content with methodological contributions alone. She devoted much effort to the parallel development of computational tools for efficient solution of such problems. Indeed, she was on the forefront of computational OR, in which well-tested computer code is implemented, taking into account both theoretical considerations and efficient data structures. A significant work of this nature is the 1973 book Fortran Codes for Mathematical Programming: Linear, Quadratic and Discrete, written jointly with Susan Powell. This work provided detailed documentation for computer implementations of optimization techniques as well as the underlying mathematical background and a suite of test problems. A subsequent 1979 publication, also with Susan Powell, offered guidance to consumers of mixed-integer programming and combinatorial programming. Her computer codes for data envelopment analysis and for the traveling salesman problem were all made freely available to the optimization community.

During Ailsa’s teaching career at the LSE, she helped to establish a two-year diploma in OR at the LSE for students from the British Iron and Steel Association. Later she instituted a mathematical programming course at the undergraduate level as well as an advanced graduate course for the MSc program. She has the distinction of being the first woman professor of operational research in Britain, and at the LSE she mentored both master’s level and PhD students, several of whom have achieved international distinction.

Other Biographies

Wikipedia Entry for Ailsa Land 

Rosenhead J. & Williams P. Ailsa Land - A Profile.  LSE OR Newsletter May p. 12 (attached by permission of The Operational Research Society)

Ailsa Land - A Profile

Ailsa Land (2019) Interview by László Végh, July 18, 2019 in Totnes, Devon, England

Ailsa Land Interview Transcript (extensively edited for clarity)