The initial design of the ship's engine room is usually done based on previous design data such as references data, optimal theoretical solutions, requirements items and design constraints. And designed data is used for the next design phase. Especially the designer modify layout based on equipment considerations, performance analysis and equipment evaluation operator. Finally, the optimal layout is selected after evaluation based on designer knowledge and experience. This time, the world's shipbuilding trade becomes very tight. To compete in the world trade market, the shipyard should make the latest innovation that can boost their companies. One of the most popular breakthroughs that make more efficient in ship design. Today, various concepts that are closely related to efficiency management are being intensely explored. On the other hand, the ship's engine room is the most complicated part of the ship so that the formulation strategy is still being developed gradually. In regards with all of that, this paper shows a new step to optimize the part arrangement in engine rooms using the genetic algorithm. Genetic algorithms used for the preparation of engine rooms in the future will improve design optimization due to minimize of the pipe length. Therefore, directly related to saving production costs. Result shows that the pipe length and pipe cost decreased about 4.26% and 3.86% respectively.