Two-Stage Optimization in a Transportation Problem

A study of the economic distribution of maize throughout South Africa is reported. Although the problem of minimizing total transportation costs in such a situation is a classical one, and its solution is well known, there was in this case a high degree of degeneracy in the system and thus the solution was not unique. Also, since a user is required to pay his own transportation costs, the various optimal solutions were not equivalent. A secondary problem thus arose, viz. that of selecting from these optimal solutions the one which would be fairest to all users. A heuristic and a goal programming method for solving this secondary problem are discussed.