D-transportation problem

A new transportation problem in which all the goods are required to be transported from sources to every destination before a given time as far as possible is posed. The problem is a goal programming problem in which one objective constraint is discrete. It is said to be D-transportation problem. This paper establishes the mathematical model of D-transportation problems, and introduces some definitions and theories, such as function, implementable solution, optimal solution, and the deviation of the optimal solution for the given time and so on. Finally, an example is provided to illustrate the proposed algorithm for solving D-transportation problems.