We in the Mathematics and Operational Research communities at ÐÓ°ÉÂÛ̳ are saddened by the loss of Emeritus Professor Ailsa Land who passed away on 16 May 2021. Professor Land played a pivotal role in the development of Operational Research and Mathematical Programming, and was one of the founders of the Operational Research group at ÐÓ°ÉÂÛ̳.
Ailsa spent her student years and entire career at ÐÓ°ÉÂÛ̳. She enrolled as a BSc Econ student in 1946 and obtained her PhD in 1956. Progressing through the academic ranks, in 1980 she was the first woman to become a chaired professor in Operational Research in the UK. She continued her association with ÐÓ°ÉÂÛ̳ as an Emeritus Professor and pursued active research work after her retirement in 1987.
Her pioneering paper with Alison Harcourt (neé Doig), published in Econometrica in 1960, introduced the branch-and-bound method in integer programming. This work has been a cornerstone in mathematical optimization, and is still a key principle in contemporary integer programming solvers and methodologies.
Together with her collaborators and students, Ailsa has made fundamental contributions to a wide range of optimization problems: quadratic programming, bicriteria decision analysis, statistical data fitting, data envelopment analysis and combinatorial auctions, to name a few. Her 1955 paper with George Morton was one of the early works to study the travelling salesman problem, and she continued to make significant contributions towards this problem over decades.
As an ÐÓ°ÉÂÛ̳ scholar and economist by training, Ailsa approached mathematical programming with an economist’s mindset. Her PhD thesis applied linear programming (also known as activity analysis at the time) to a coal transportation problem, and the branch-and-bound method was motivated by a model on refinery operations for British Petroleum.
Besides her methodological contributions, she was also a pioneer in computational Operational Research. Once computers became available at the University of London and then at ÐÓ°ÉÂÛ̳, she started developing well-tested and robust computer implementations of important optimization methods. A significant early work with her student Susan Powell was 'Fortran Codes for Mathematical Programming: Linear, Quadratic and Discrete' in 1973. Her computer codes were all made freely available for the OR community.
At ÐÓ°ÉÂÛ̳, together with George Morton she initiated a two-year masters degree in Operational Research in collaboration with the British Iron and Steel Research Association; their graduate trainees formed the initial core of students on the degree. Ailsa’s relaxed and supportive style made the growing OR group a remarkably harmonious and collaborative venture. She established an active research group in Operational Research, supervising many masters and PhD students, many of whom rose to positions of academic leadership across the world. The Ailsa Land Prize is awarded for the best overall performance by a student on the MSc Operations Research & Analytics in the Department of Mathematics at ÐÓ°ÉÂÛ̳.
Her work was recognised by the Harold Lardner Prize of the Canadian Operational Research Society in 1994, and by the Beale Medal of the British OR Society in 2019. Her achievements were celebrated at the Society’s Beale Lecture in February 2021. She will be the posthumous recipient of the EURO 2021 Gold Medal, the highest distinction within Operational Research in Europe, awarded by the Association of European Operational Research Societies.
Ailsa is survived by her husband Frank Land OBE, three children, seven grandchildren, and two great-grandchildren. Ailsa and Frank met as students at ÐÓ°ÉÂÛ̳, and married in 1953; Frank was a pioneer in information systems research and is a Professor Emeritus at ÐÓ°ÉÂÛ̳.
Jonathan Rosenhead (Emeritus Professor of Operational Research) and László Végh (Professor of Mathematics)
ÐÓ°ÉÂÛ̳ has a condolence page on which you can leave comments and wishes . You can also read the INFORMS biography and interview with Ailsa . The Guardian published an obituary piece on 14 June 2021, which you can read .