Optimization Methods: Linear Programming and Project Analysis

Classified in Design and Engineering

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Operations Research and Linear Programming Fundamentals

  • Operations Research (OR) Systems: Exact methods, heuristics, deterministic methods, and probabilistic models.
  • Linear Programming (LP) Introduction:
    • Elements of the linear model.
    • Feasible region (or possible region).
    • Feasible solutions and LP assumptions.

Simplex Method and Duality

LP Certainty Programming and Geometry

  • Isostability line and Iso-cost line.
  • Possible cases of optimal solutions.
  • Heuristic algorithms versus exact algorithms.
  • Convex sets and their properties.
  • Basic canonical form of the system.

Solutions and Simplex Basics

  • Non-basic and basic variables.
  • Fundamental Simplex Theorems (First and Second).
  • Properties of extreme points of the feasible region.
  • Detection of non-optimal, feasible, and multiple solutions.

Advanced Simplex Techniques

  • Detection of degenerate cases.
  • The Two-Phase Simplex Method.
  • Linear programming model problems.

Duality and Sensitivity Analysis

  • Relationship between the primal and dual problems.
  • Interpretation of shadow prices (dual prices).
  • Complementary Slackness Theorem and Unboundedness Theorem.
  • Cost interpretation.
  • Consequences of coefficient changes in the objective function (for basic variables).
  • Consequences of technological changes (for non-basic variables).

Transportation and Assignment Problems

Transportation Problem Modeling

  • The Transportation Table.
  • Methods to calculate the initial feasible solution.
  • What happens if new variables or constraints are added?
  • Transportation problem structure and closed circuits.
  • Comparison methods for solution evaluation.
  • Degenerate transportation problems.
  • Resolution of maximization transportation problems.

Optimal Solution Methods

  • Methods for finding the optimal solution.
  • Exchanges between basic variables.
  • The Hungarian Test (for assignment problems).

Project Management (PERT/CPM)

PERT/CPM Elements

  • Basic techniques for project management.
  • Precedence analysis in PERT.
  • Key time metrics: Early Time and Late Time for nodes.
  • Chain, cycle route, and critical path.
  • Total float of an activity.
  • Activities with zero slack ($M_{ij} = 0$).
  • Activity duration uncertainty (PERT formulation).

Network Components

  • Connected nodes and arcs.
  • Arc capacity.
  • Critical Path definition.
  • Activity notation: $t_{ij}$ (e.g., $t_{Lij} = t_{Eij}$).
  • Free float (e.g., activities where $t_{Lij} = 0$).

Network Flow and Integer Programming

Flow and Routing Problems

  • Maximum Flow Problem.
  • Feasible flow conditions.
  • Vehicle Routing Problem (VRP).
  • Shortest Path Problem.
  • Fixed Charge Problem.

Integer Programming (IP)

  • Characteristics of whole programming models (IP).
  • Types of IP and basic model assumptions.
  • The Knapsack Problem (storage/inventory).
  • Traveling Salesman Problem (TSP).
  • Why Simplex cannot apply to certain problems (e.g., IP).
  • Examples of problem types, characteristics, and resolution methods.

Inventory Management and Diagnostics

Inventory and Cost Analysis

  • Logistics function.
  • Sensitivity cost and storage cost.
  • Economic Order Quantity (EOQ) model.
  • Shortage cost (cost of rupture).
  • Total Economic Cost (TEC) expression and amendments.
  • Point-to-point request or order systems.

LP Diagnostics and Advanced Concepts

  • Adjacent basic solutions in degenerate linear models.
  • Detection of unbounded problems.
  • Detection of infeasible regions.
  • Sensitivity analysis.

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