Engineering changes are driving forces of product development and improvement in any company. In shipbuilding projects, engineering changes are introduced throughout the project duration and cannot be planned or introduced to the next production run since products are only made once and never repeated. A lot of research exists on engineering changes and their management in general, but the focus of this study is to increase the awareness and understanding of the engineering changes specifically in shipbuilding projects. In this study, an in-depth investigation of engineering changes and aspects having influence on engineering change implementation performance in Norwegian shipbuilding company was performed. The findings indicate that engineering changes and their implementation performance are related to such aspects as market segment, supply chain network, design maturity, overlapping project stages, and timing of EC occurrence in the project. These aspects, their influence on the number of ECs, and EC implementation and performance, are described and analyzed in the paper, and future research plans are presented.