Contents

Preface Hello world!

Introduction Fundamental Questions

Introduction Planning versus Operations

Introduction Modeling

Introduction Logistic System

Customer Assigment Models

Traveling Salesman Problem

Traveling Salesman Problem: Bounds

Vehicle Scheduling

Vehicle Scheduling: Cluster-First-and-Then-Route Approach

Hello world!

Welcome to Distribution Systems. This is a new beginning.

Fundamental Questions

The complex interactions that occur in large distribution systems prevent their analysis as one entity. The only practical way to resolve the question of “Can a distribution system be improved?” is to break it into a series of interrelated smaller questions, The natural place to start is by defining the geographical relationships among the various components of the system, The following are typical questions in distribution analysis whose answers provide significant improvement in both service and cost (Jarvis and Ratliff, 1992, pp. 2199-2201).

• Where are customers, warehouses, and plants?
• What are their relevant characteristics?
• What is the profit associated with each customer?
• Are customer service requirements reasonable?
• Is the delivery strategy reasonable?
• Is the allocation of customers to warehouses appropriate?
• Is in-bound mode selection appropriate?
• Is in-bound sourcing appropriate?
• Is the number, configuration, and location of warehouses right?
• Is the number, configuration, and location of plants right?

The key requirements for determining how to improve a distribution system are: insights as to what alternatives should be considered and computer models that allow flexibility in generating, modifying, and evaluating the alternatives.

Jarvis, John J. and Ratliff, Donald. Distribution and Logistics, in Salvendy, Gavriel ed. Handbook of Industrial Engineering, 2nd. ed, John Wiley and Sons, New York, 1992, pp. 2199-2214.

2007-02-15 10:45 pm

Planning versus Operations

Strategic decisions

• location and sizing of facilities
• fleet selection and sizing
• analysis of production and/or inventory capabilities and needs
• financing requirements

Tactical decisions

• vehicle scheduling
• routing
• loading
• overtime requirements

Jarvis, John J. and Ratliff, Donald. Distribution and Logistics, in Salvendy, Gavriel ed. Handbook of Industrial Engineering, 2nd. ed, John Wiley and Sons, New York, 1992, pp. 2201-2202.

2007-02-20 6:21 pm

Modeling

Simulation and optimization, Jarvis and Ratliff (1992, p. 2202)

Aggregation and decomposition, Jarvis and Ratliff (1992, p. 2202)

Alternatives generation and evaluation, Jarvis and Ratliff (1992, p. 2203)

Jarvis, John J. and Ratliff, Donald. Distribution and Logistics, in Salvendy, Gavriel ed. Handbook of Industrial Engineering, 2nd. ed, John Wiley and Sons, New York, 1992, pp. 2199-2214.

2007-02-27 5:05 pm

Logistic System

Definition, Eilon et al. (1971, p. 1)

Importance, Eilon et al. (1971, p. 1)

Illustration, Eilon et al. (1971, pp. 1-2)

Nomenclature, Eilon et al. (1971, p. 2)

Total cost function, Eilon et al. (1971, pp. 3-7)

Problems in distribution management, Eilon et al. (1971, pp. 7-8)

Eilon, S., Watson-Gandy, C. D. T. and Christofides, N. Distribution Management: Mathematical Modelling and Practical Analysis. Griffin, London, 1971.

2007-03-06 5:10 pm

Customer Assigment Models

Constraints and objective, Jarvis and Ratliff (1992, p. 2203)

Fixed supply points, Jarvis and Ratliff (1992, p. 2203)

Assumptions, Jarvis and Ratliff (1992, p. 2203)

Single level and multiple sourcing, Jarvis and Ratliff (1992, pp. 2203-2204)

Mathematical formulation: transportation model, Jarvis and Ratliff (1992, pp. 2203-2204)

Single level and single sourcing, Jarvis and Ratliff (1992, pp. 2204-2205)

Mathematical formulation, Jarvis and Ratliff (1992, pp. 2203-2204)

Multiple level, Jarvis and Ratliff (1992, pp. 2204-2207)

Mathematical formulation, Jarvis and Ratliff (1992, pp. 2205-2206)

Multiple products, Jarvis and Ratliff (1992, p. 2206)

Jarvis, John J. and Ratliff, Donald. Distribution and Logistics, in Salvendy, Gavriel ed. Handbook of Industrial Engineering, 2nd. ed, John Wiley and Sons, New York, 1992, pp. 2199-2214.

2007-03-06 5:22 pm

Traveling Salesman Problem

Problem statement, Evans and Minieka (1992, p. 317) and Eilon et al. (1971, p. 113)

Problem statement as a graph, Evans and Minieka (1992, p. 317)

Problem classifications, Evans and Minieka (1992, pp. 317-318) and Eilon et al. (1971, p. 113)

Typical examples, Evans and Minieka (1992, pp. 318-318)

Properties of the traveling salesman problem, Evans and Minieka (1992, pp. 320-328) and Eilon et al. (1971, pp. 113-116)

Generating solutions by sequential tour building, Eilon et al. (1971, pp. 116-117)

Generating solutions by subtour contraction, Eilon et al. (1971, p. 118)

Dynamic programming model, Eilon et al. (1971, pp. 118-121)

Solved small numerical example, Eilon et al. (1971, pp. 121-123)

Branch and bound algorithm, Eilon et al. (1971, pp. 123-128)

Solved small numerical example, Eilon et al. (1971, pp. 129-132)

Eilon, S., Watson-Gandy, C. D. T. and Christofides, N. Distribution Management: Mathematical Modelling and Practical Analysis. Griffin, London, 1971.

Evans, James R. and Minieka, Edward. Optimization Algorithms for Networks and Graphs, 2nd ed. Marcel Dekker, New York, 1992.

2007-04-10 12:09 am

Traveling Salesman Problem: Bounds

Bounds for the traveling salesman problem, Eilon et al. (1971, pp. 140-142)

Shortest spanning tree bound, Eilon et al. (1971, p. 141)

Assignment problem bound, Eilon et al. (1971, pp. 141-142)

Sum of the shortest links, Eilon et al. (1971, p. 142)

Improving the bounds and solving the traveling salesman problem, Eilon et al. (1971, pp. 142-145)

Improvement to the shortest spanning tree bound, Eilon et al. (1971, p. 143)

Improvement to the assignment problem bound, Eilon et al. (1971, pp. 143-145)

Eilon, S., Watson-Gandy, C. D. T. and Christofides, N. Distribution Management: Mathematical Modelling and Practical Analysis. Griffin, London, 1971.

2007-04-10 12:11 am

Vehicle Scheduling

Problem statement, constraints and subproblems, Eilon et al. (1971, pp. 180-181)

Covering and partitioning, Jarvis and Ratliff (1992, pp. 2207-2209)

Mathematical formulation, Jarvis and Ratliff (1992, pp. 2207-2208)

Small numerical example, Jarvis and Ratliff (1992, p. 2208)

Additional constraints, Jarvis and Ratliff (1992, p. 2209)

Eilon, S., Watson-Gandy, C. D. T. and Christofides, N. Distribution Management: Mathematical Modelling and Practical Analysis. Griffin, London, 1971.

Jarvis, John J. and Ratliff, Donald. Distribution and Logistics, in Salvendy, Gavriel ed. Handbook of Industrial Engineering, 2nd. ed, John Wiley and Sons, New York, 1992, pp. 2199-2214.

2007-04-09 11:15 pm