SOLUTION METHODS

Before further discussion of the vehicle routing problem, let us take some time on discussing some general concepts on the engineering design process and solution methods for logistics-related problems.

Engineering Design Process

1. Formulate the problem
2. Collect data and analyze the problem
3. Generate alternative solutions
4. Evaluate design alternatives
5. Select the preferred design(s)
6. Specify the solution
7. Evaluate the design in use

Modeling/Models

The engineer/analyst typically builds a model of the real world to better understand and to improve. A model is an abstract representation of a real world system. Since models are easier to manipulate, they provide insight.

Solution Methods

Models are analyzed and solved using algorithms. An algorithm can be defined as a set of rules to determine a system configuration. For example, a very simple algorithm for cooking omelet would be as follows:

• Whisk together the eggs until blended
• Add salt and pepper to taste, and whisk another 5 seconds
• In an 8-inch frying pan or skillet, melt the butter over medium-high heat.
• Add the egg mixture and cook for 30 seconds
• If you wish to fill the omelet,
  • add the filling now
• Cook another 30 seconds

Algorithms can be classified according to several characteristics:

Types of Solution Algorithms

• Manual
• Spreadsheet
• Simulation
• Optimization & Heuristics
• Expert Systems