Core Concepts
Linear Programming
A mathematical method for maximizing or minimizing a linear objective function subject to linear constraints.
Simplex Algorithm
The most common method for solving linear programming problems, developed by George Dantzig.
Integer Programming
LP where some or all variables must be integers. Much harder to solve (NP-hard).
Network Flow Models
Problems involving flows through networks: shortest path, maximum flow, minimum cost flow.
Queuing Theory
The mathematical study of waiting lines, used to optimize service systems.
Game Theory
The study of strategic decision-making between competing actors.
Worked Examples & Applications
Transportation Problem: Minimize: ΣΣ Cᵢⱼ × Xᵢⱼ, Subject to: ΣXᵢⱼ = Sᵢ (supply), ΣXᵢⱼ = Dⱼ (demand), Xᵢⱼ ≥ 0. Solved using the Transportation Simplex Method.
Little's Law: L = λ × W, where L = average number of customers in system, λ = average arrival rate, W = average time in system. Example: If 10 customers arrive per hour and each stays 30 min, L = 10 × 0.5 = 5 customers on average.
Practice Questions
Q: What is the difference between LP and IP? A: In LP, variables can take any real value. In IP, some/all variables must be integers, making it NP-hard.
Q: State Little's Law. A: L = λW — The average number of items in a system equals the arrival rate multiplied by the average time spent in the system.