This document describes a transportation model, a special type of linear programming problem where commodities are shipped from sources to destinations to minimize total shipping costs while meeting supply and demand requirements. It explains that the transportation model can be expressed in a matrix format showing unit shipping costs from suppliers to demanders. The document also outlines the North-West-Corner Method for solving transportation models, which allocates shipments to the northwest corner variable and adjusts remaining supply and demand at each step until all units are allocated.

2. A special class of the LP problem
Deals with the situation in which commodities
are shipped from sources to destinations.
Objective is to determine the amounts shipped
from each source to each destination.
Need to minimise the total shipping cost.
Need to satisfy both the supply limits and the
demand requirements.

3. The figure shows a classic transportation model expressed in the
matrix format. Three suppliers with 15 units each of some
commodity must ship to three demanders with specified demand.
The numbers in the table are the unit shipping cost. The goal is to
find a distribution schedule that minimizes the total cost of
shipments.

4. The North-West-Corner Method
Step 1. Allocate as much as possible to the variable, xij, in
the northwest corner of the (remaining) table
Step 2. Adjust the associated amounts of supply and
demand by subtracting the allocated amount
Step 3. If all units have been allocated stop;