Professor Adam Letchford
Professor of Analytics and OptimisationResearch Overview
My research is in optimisation, i.e., finding the best solution to problems that have a huge (possibly infinite) number of solutions. Optimisation is an inter-disciplinary subject, lying at the interface between Operational Research, Computer Science, Applied Mathematics and Engineering. I concentrate mainly on methods for solving optimisation problems to proven optimality, rather than heuristic methods. I have a particular interest in combinatorial optimisation problems, i.e., problems in which variables are restricted to take integer (whole-number) values.
Web Links
Personal web page: www.lancs.ac.uk/staff/letchfoa
My Role
- Professor of Analytics and Optimisation
- LUMS Director of Research Enhancement
Current Teaching
MSCI534: Optimisation and HeuristicsSTOR607: Deterministic Optimisation
External Roles
- Fellow of the Operational Research Society (since 2009).
- Member of the EPSRC Peer Review College (since 2006)
- Member of the UKRI Future Leaders Peer Review College (since 2018)
- Associate Editor of EURO Journal on Computational Optimization (since 2012)
- Associate Editor of the Open Journal on Mathematical Optimization (since 2018)
Qualifications
- BA (Hons) Linguistics & Psychology, Nottingham, 1989
- MSc Operational Research, Lancaster, 1993
- PhD Management Science, Lancaster, 1997
PhD Supervisions Completed
- Congzheng (Joshua) Liu (2023) Extensions to newsvendor problems.
- Thu Huong Dang (2022) Exact and heuristic approaches to arc routing problems.
- M. Hasan Mansoor (2022) Combinatorial optimisation: relaxation and heuristics.
- Georgia Souli (2020) New valid inequalities for knapsack and fixed-charge problems.
- Zhaoyu (Joe) Zhong (2018) Optimal resource allocation in base stations for mobile wireless communications.
- Robert Maidstone (2016) Efficient analysis of complex change-point problems.
- Terry James (2015) Control of multi-class queueing systems with abandonments and adversarial customers.
- Saeideh Nasiri (2014) Vehicle routing on real road networks.
- Franklin Djeumou Fomeni (2014) The quadratic knapsack problem and related problems.
- Sebastian J. Miller (2013) Simple plant location problem: heuristics, algorithms and reductions.
- Konstantinos Kaparis (2008) Knapsack problems: inequalities, separation and heuristics.
- Amar Oukil (2008) Exploiting sparsity in vehicle routing algorithms.
- Daniel .J. Grainger (2008) Contributions to quadratic 0-1 programming.
- Nicholas A. Pearson (2006) Minimum cuts, circuits and tours in planar graphs.
PhD Supervision Interests
Most of my PhD students work on exact solution algorithms for NP-hard optimisation problems. Candidates need to be comfortable with mathematics. Experience in programming (in, e.g., C, Julia, MatLab or Python) is highly desirable, as is basic knowledge of linear algebra and graph theory.
Newsvendor Problems
01/01/2020 → 31/12/2022
Research
STORi: Route optimisation for waste collection
01/10/2019 → 31/03/2023
Research
The 2013 Newton Institute Programme on Polynomial Optimisation
15/07/2013 → 09/08/2013
Other
Mixed-Integer Nonlinear Programming
01/10/2009 → …
Research
Fellowship: The Cut Polytope and Related Convex Bodies
01/08/2006 → 31/07/2011
Research
Algorithms for Vehicle Routing Problems
01/01/2003 → …
Research
Algorithms for the Travelling Salesman Problem
01/01/1999 → …
Research
Cutting-Plane Approaches to Integer Programming
01/01/1997 → …
Research
Integer Programming and Combinatorial Optimisation
01/01/1900 → …
Research
36th Conference of the European Chapter on Combinatorial Optimization
Participation in conference - Academic
4th Joint IMA/ORS Conference on the Mathematics of Operational Research
Participation in conference -Mixed Audience
4th Joint IMA/ORS Conference on the Mathematics of Operational Research
Participation in conference -Mixed Audience
4th Joint IMA/ORS Conference on the Mathematics of Operational Research
Participation in conference -Mixed Audience
A new approach to quadratic unconstrained binary optimisation
Invited talk
Insertion heuristics for a class of dynamic vehicle routing problems
Invited talk
Insertion heuristics for a class of dynamic vehicle routing problems
Invited talk
University of L'Aquila
Visiting an external academic institution
Improving a constructive heuristic for the general routing problem
Invited talk
2022 International Conference on Optimization and Decision Science (ODS 2022)
Participation in conference - Academic
4th Workshop on Arc Routing Problems
Participation in conference - Academic
2022 STOR-i Workshop on Prediction and Optimisation
Participation in conference -Mixed Audience
34th Conference of the European Chapter on Combinatorial Optimization (ECCO XXXIV)
Participation in conference - Academic
3rd IMA/ORS Conference on the Mathematics of Operational Research
Participation in conference -Mixed Audience
34th Annual Conference of the Belgian Operational Research Society (ORBEL34)
Participation in conference - Academic
61st Annual Conference of the Operational Research Society (OR61)
Participation in conference -Mixed Audience
30th European Conference on Operational Research (EURO XXX)
Participation in conference - Academic
2nd Joint IMA/ORS Conference on the Mathematics of Operational Research
Participation in conference -Mixed Audience
University of Pisa
Visiting an external academic institution
60th Annual Conference of the Operational Research Society (OR60)
Participation in conference -Mixed Audience
23rd International Symposium on Mathematical Programming (ISMP XXIII)
Participation in conference - Academic
23rd International Symposium on Mathematical Programming (ISMP XXIII)
Participation in conference - Academic
5th International Symposium on Combinatorial Optimization (ISCO)
Participation in conference - Academic
5th International Symposium on Combinatorial Optimization (ISCO)
Participation in conference - Academic
1st Joint IMA/ORS Conference on the Mathematics of Operational Research
Participation in conference -Mixed Audience
Bit representations of mixed-integer quadratic programs
Invited talk
20th Combinatorial Optimisation Conference (CO2016)
Participation in conference - Academic
4th International Symposium on Combinatorial Optimization (ISCO)
Participation in conference - Academic
20th Combinatorial Optimisation Conference (CO2016)
Participation in conference - Academic
27th European Conference on Operational Research (EURO XXVII)
Participation in conference - Academic
17th British-French-German Optimisation Conference (BFG 2015)
Participation in conference - Academic
An introduction to approximation algorithms (and inapproximability)
Invited talk
Mathematical Programming (Journal)
Editorial activity
Stronger multi-commodity flow formulations of the capacitated vehicle routing problem
Invited talk
LANCS International Workshop on Discrete and Nonlinear Optimisation
Participation in conference -Mixed Audience
Some unbounded convex sets arising in non-convex MIQP
Invited talk
Strengthening the reformulation-linearisation technique with cutting planes
Invited talk
18th Combinatorial Optimisation Conference (CO2012)
Participation in conference - Academic
25th European Conference on Operational Research (EURO XXV)
Participation in conference - Academic
25th European Conference on Operational Research (EURO XXV)
Participation in conference - Academic
10th International Conference on Applied Mathematical Optimization and Modelling (APMOD 2012)
Participation in conference - Academic
Second order cone programming and its applications
Invited talk
EURO Journal on Computational Optimization (Journal)
Editorial activity
25th European Conference on Operational Research (EURO XXV)
Participation in conference - Academic
21st International Symposium on Mathematical Programming (ISMP)
Participation in conference - Academic
Operations Research (Journal)
Editorial activity
10th International Conference on Applied Mathematical Optimization and Modelling (APMOD 2012)
Participation in conference - Academic
8th Mixed-Integer Programming Workshop (MIP 2011)
Participation in conference - Academic
SIAM Conference on Optimization
Participation in conference - Academic
LANCS Workshop on Modelling and Solving Complex Optimisation Problems
Participation in conference -Mixed Audience
Reformulating mixed-integer quadratically-constrained quadratic programmes
Invited talk
Convex relaxations of the stable set problem
Invited talk
A tutorial on mixed-integer non-linear programming
Invited talk
Mixed-integer non-linear programming: a survey
Invited talk
Reformulation of 0-1 quadratically constrained quadratic programs
Invited talk
An introduction to second-order cone programming
Invited talk
London School of Economics
Visiting an external academic institution
14th Conference on Integer Programming and Combinatorial Optimization (IPCO XIV)
Participation in conference - Academic
2010 Joint ECCO-CO Conference
Participation in conference - Academic
Optimisation over cones
Invited talk
The Travelling Salesman Problem
Invited talk
2nd LANCS Workshop on Discrete and Nonlinear Optimisation
Participation in conference -Mixed Audience
2nd LANCS Workshop in Heuristic Understanding
Participation in conference -Mixed Audience
2010 Joint ECCO-CO Conference
Participation in conference - Academic
Algorithmic Aspects in Information and Management
Participation in conference - Academic
51st Annual Conference of the Operational Research Society (OR51)
Participation in conference -Mixed Audience
23rd European Conference on Operational Research (EURO XXIII)
Participation in conference - Academic
Fifty years of cutting planes
Invited talk
On non-convex quadratic programming with box constraints
Invited talk
4th International Network Optimization Conference (INOC 2009)
Participation in conference - Academic
1st Student Conference on Operational Research
Participation in conference - Academic
1st LANCS Workshop on Discrete and Nonlinear Optimisation
Participation in conference -Mixed Audience
4th International Network Optimization Conference (INOC 2009)
Participation in conference - Academic
Recent progress on knapsack-based cutting planes
Invited talk
23rd European Conference on Operational Research (EURO XXIII)
Participation in conference - Academic
51st Annual Conference of the Operational Research Society (OR51)
Participation in conference -Mixed Audience
Discrete Optimization (Journal)
Editorial activity
Bonn Workshop on Combinatorial Optimisation
Participation in conference - Academic
Binary positive semidefinite matrices and some related polytopes
Invited talk
Mixed-Integer Programming Workshop (MIP 2008)
Participation in conference - Academic
13th Conference on Integer Programming and Combinatorial Optimization (IPCO XIII)
Participation in conference - Academic
15th Combinatorial Optimisation Conference (CO2008)
Participation in conference - Academic
12th Aussois Workshop on Combinatorial Optimisation
Participation in conference - Academic
Discrete Applied Mathematics (Journal)
Editorial activity
Mathematical Programming Computation (Journal)
Editorial activity
2nd INFORMS Optimization Society Conference (2008)
Participation in conference - Academic
ALIO/EURO Conference on Combinatorial Optimization
Participation in conference - Academic
An introduction to conic programming
Invited talk
Optimization 2007
Participation in conference - Academic
3rd International Network Optimization Conference (INOC 2007)
Participation in conference - Academic
Stronger upper bounds for the maximum stable set problem
Invited talk
Discrete Optimization (Journal)
Editorial activity
Semidefinite programming and combinatorial optimization
Invited talk
21st European Conference on Operational Research (EURO XXI)
Participation in conference - Academic
Canadian Operational Research Society Annual Conference (CORS)
Participation in conference - Academic
Spring School on Vehicle Routing
Participation in conference - Academic
Algorithms for planar graphs
Invited talk
Journées de l'Optimisation 2005
Participation in conference - Academic
Vehicle routing games
Invited talk
Planar graphs and the traveling salesman problem
Invited talk
Solving discrete optimization problems by branch-and-cut
Invited talk
Vehicle routing games
Invited talk
Computational Optimization and Applications (Journal)
Editorial activity
11th Conference on Integer Programming and Combinatorial Optimization (IPCO XI)
Participation in conference - Academic
Mixed-Integer Programming Workshop
Participation in conference - Academic
Exploring the relationship between max-cut and stable set relaxations
Invited talk
The traveling salesman problem: inequalities and separation
Invited talk
Bertinoro Workshop on Combinatorial Optimisation
Participation in conference - Academic
The traveling salesman problem: inequalities and separation
Invited talk
Solving discrete optimization problems by branch-and-cut
Invited talk
13th Combinatorial Optimisation Conference (CO2004)
Participation in conference - Academic
8th Aussois Workshop on Combinatorial Optimisation
Participation in conference - Academic
13th Combinatorial Optimisation Conference (CO2004)
Participation in conference - Academic
The traveling salesman problem: inequalities and separation
Invited talk
The traveling salesman problem: inequalities and separation
Invited talk
Solving discrete optimization problems by branch-and-cut
Invited talk
34th Annual Conference of the Italian Operational Research Society (AIRO)
Participation in conference - Academic
18th International Symposium on Mathematical Programming (ISMP 2003)
Participation in conference - Academic
Solving discrete optimisation problems by branch-and-cut
Invited talk
2nd Conference on Routing and Location (CORAL)
Participation in conference - Academic
On traveling salesman games
Invited talk
Mathematical Programming (Journal)
Editorial activity
16th Conference of the International Federation of Operational Research Societies (IFORS)
Participation in conference - Academic
Integer Programming Conference in Honor of Egon Balas
Participation in conference - Academic
9th Conference in Integer Programming and Combinatorial Optimization (IPCO IX)
Participation in conference - Academic
6th Aussois Workshop on Combinatorial Optimisation
Participation in conference - Academic
15th Annual Conference of the Italian Operational Research Society (AIRO)
Participation in conference - Academic
Primal separation algorithms
Invited talk
5th Aussois Workshop on Combinatorial Optimization
Participation in conference - Academic
Associazione Italiana di Ricerca Operativa (External organisation)
Member of an organisation
17th International Symposium on Mathematical Programming (ISMP)
Participation in conference - Academic
12th Combinatorial Optimisation Conference (CO2000)
Participation in conference - Academic
4th Aussois Workshop on Combinatorial Optimisation
Participation in conference - Academic
The Operational Research Society (External organisation)
Member of an organisation
The polyhedral approach to the TSP
Invited talk
Symposium on Operations Research
Participation in conference - Academic
7th Conference on Integer Programming and Combinatorial Optimization (IPCO VII)
Participation in conference - Academic
3rd Aussois Workshop on Combinatorial Optimization
Participation in conference - Academic
Oberwolfach Workshop on Combinatorial Optimisation
Participation in conference - Academic
11th Combinatorial Optimisation Conference (CO98)
Participation in conference - Academic
2nd Aussois Workshop on Combinatorial Optimisation
Participation in conference - Academic
10th Combinatorial Optimisation Conference (CO96)
Participation in conference - Academic
37th Annual Conference of the Operational Research Society (OR37)
Participation in conference -Mixed Audience
Fellow of the Operational Research Society (FORS)
Fellowship awarded competitively
Recipient of IBM Faculty Award
Prize (including medals and awards)
Centre for Transport & Logistics (CENTRAL), STOR-i Centre for Doctoral Training
- Centre for Transport & Logistics (CENTRAL)
- DSI - Foundations
- Optimisation
- STOR-i Centre for Doctoral Training