What is Operations Research

Terminology, History and Applications

Terminology• The British/Europeans refer to "operational research", the

Americans to "operations research" - but both are often shortened to just "OR".

• Another term used for this field is "management science" ("MS"). In U.S. OR and MS are combined together to form "OR/MS" or "ORMS".

• Yet other terms sometimes used are "industrial engineering" ("IE") and "decision science" ("DS").

History of OR

• OR is a relatively new discipline. • 90 years ago it would have been possible to study

mathematics, physics or engineering at university it would not have been possible to study OR.

• It was really only in the late 1930's that operational research began in a systematic way.

Operations Research Models

Deterministic Models Stochastic Models• Linear Programming • Discrete-Time Markov Chains• Network Optimization • Continuous-Time Markov Chains• Integer Programming • Queueing• Nonlinear Programming • Decision Analysis

What is Operations Research/ Management Science?

• OR/MS is the scientific approach to execute decision making, which consist of

• The art of mathematical modeling of complex situations

• The science of the development of solution techniques used to solve these models

• The ability to effectively communicate the results to the decision maker

What Do We do

1. OR professionals aim to provide rational bases for decision making by seeking to understand and structure complex situations and to use this understanding to predict system behavior and improve system performance.

2. Much of this work is done using analytical and numerical techniques to develop and manipulate mathematical and computer models of organizational systems composed of people, machines, and procedures.

OR Applications

• Scheduling aircraft and personal in response to groundings and delays

• Planning production to meet demand• Scheduling equipment and workforce in

industry• Adjusting nurse schedules in light of daily

fluctuations in demand

The Traveling Salesman Problem

Example: Traveling Salesman Problem

• Traveling Salesman Problem (TSP): Given a complete graph with nonnegative edge costs, Find a minimum cost cycle visiting every vertex exactly once.

• Application (Example): Given a number of cities and the costs of traveling from any city to any other city, what is the cheapest round-trip route that visits each city exactly once and then returns to the starting city

The Mission: A Tour Around the World

The Problem: Traveling Costs Money

1000$

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2

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Cost=15

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Cost=11

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Cost=18