To develop a computer tool that will give the best ship design using an optimization technique is one of the objects of the FIRST project. Choosing a containership design as a test case, the Design Optimization Tools (DOT) package is used as the optimization tool. The problem is tackled from the ship owner's point of view. The required freight rate is chosen as the objective function because the most important thing that concerns the ship owner is whether the ship will make a profit or not, and if so, how much profit it can make. DOT, as well as any other numerical optimization tool, only gives an approximation of the optimum design and uses numerical approximation during the optimization. It is very important for the users to formulate carefully the optimization problem so that it will give a stable and reasonable solution. Development of a geometric module and choosing suitable empirical formulas for performance evaluation are also major issues of the project.