# Operations Research

The discipline of Operations Research (OR) provides a scientific approach to decision making. Also known by titles such as Management Science, or Logistics, Operations Research involves formulating mathematical models of decision making problems, and developing or applying mathematical tools to obtain solutions. Many businesses and all large complex organisations face difficult decisions on a daily basis. For example, a manufacturing company must decide how much of each product it should be making at each point in time, how many products of each type it should keep in inventory, by what modes of transport and what routes it should distribute its product, which combination of new product development projects it should fund in the next year, which workers should be rostered on which shifts, how much overtime will be required of each worker, when it should replace or repair its equipment, and so on. The decisions made interact with each other and may have complex repercussions that are difficult to evaluate. Each decision involves making a trade-off between competing activities, often vying for limited resources. For example, a decision to maintain steady production levels may reduce production costs but increase inventory costs, while a decision to produce a large quantity of one product may deplete stock of a component needed for the timely production of another product. The mathematical techniques used in Operations Research are drawn from areas of mathematics such as Optimisation, Optimal Control and Probability and Statistics. The area of Optimisation, which is concerned with the mathematical problem of minimising or maximising a function or functions subject to constraints, plays a particularly important role since the objective of many decision making problems is to determine the minimum or maximum out of a set of alternatives; for example a production company might wish to make decisions so as to minimise its transportation costs or to maximise its workers' job satisfaction. Major subfields of Optimisation which are critical in solving Operations Research problems are Mathematical Programming, Dynamic Programming, Network Optimisation and Stochastic Modelling, all of which are the subject of active research by members and graduate students of the Operations Research Group in the Department of Mathematics and Statistics.

## Seminar series

Dr Mark FACKRELL (Senior Lecturer)
Research interests: Game theory, Healthcare modelling, Matrix-analytic methods, Operations Research, Stochastic Modelling
Prof Sanming ZHOU (Professor)
Research interests: Algebraic Combinatorics, Algebraic Graph Theory, Graph Structure and Dynamics, Network Optimisation, Operations Research, Random Graph Processes, Theoretical Computer Science
Prof Peter TAYLOR (Professor)
Research interests: Complex Networks, Markov decision processes, Matrix-analytic methods, Mechanism design, Optimisation and control, Parameter estimation, Queueing theory, Stochastic modelling of biological/environmental systems, epidemics, telecommunications systems and emergency management systems
A/Prof Sophie HAUTPHENNE (Associate Professor)

Dr Lele (Joyce) ZHANG (Lecturer)
Research interests: Operations Research, Transport network modelling and optimisation
A/Prof Alysson COSTA (Associate Professor)
Research interests: Mixed Integar Programming theory and applications to industry and public decision-making
A/Prof Charl RAS (Associate Professor)
Research interests: Combinatorial optimisation, Discrete and computational geometry, Shortest network design, Survivable networks
Prof Kate SMITH-MILES (Associate Dean (Industry & Enterprise) / Professor)
Research interests: Combinatorial optimisation, Continuous optimisation , Dimensional reduction, Generation of hard test instances , Machine Learning, Mathematical modelling, Multi-objective optimisation, Numerical linear algebra, Operations Research, Parameter estimation, Performance evaluation
Dr Matthew TAM (Senior Lecturer)
Research interests: Monotone operator theory, Nonsmooth optimisation, Symbolic computation
Dr Yuji SAIKAI (Teaching Specialist)

## Honorary Staff

Dr Moshe SNIEDOVICH
Principal Fellow (Associate)
Dr Andre COSTA
Fellow (Associate)
Dr Olivia SMITH
Fellow (Associate)

## Visitors

Dr Yangming LI (Department of Mathematics, Guangdong University of Education)
Professor Zhiyuan (Terry) LIU (Southeast University)