The electronic system in automobiles has become more important in providing safety, comfort and entertainment, at the same time less harmful to the environment. Due to the fact that there are varieties in automobile electronic devises, product development has become more complex. For example, shortening product development period while maintaining quality and fulfilling requirements of each company are all important issues. The development of automobile electronic products cannot only emphasize on functionality but also need to be more customer-oriented to fulfill the needs and expectations of the users. The initial phase of product development should focus on confirming the types of products with clients in order to develop and manufacture into what have been expected. The goal of product development expected by the market has obvious differences with the actual products that have been manufactured. The reason for the differences is the emphasis on functionality during the initial phase of product development. Also, the development process has focused mainly on technological development instead of customer expectations and the changes that occur during the product life cycle, which brings in the need for ¡§Requirements Management.¡¨ Problems such as large amount of development cost, compensation, loss of order and reliability can be resolved through the application of ¡§Requirements Management.¡¨ Through observation and interviews with management team and project managing engineers, what is lacking is the method of demand analysis for system engineer of suppliers during the demand analysis stage to better analyze customer needs and to combine with existing system; thus managers can utilize the requirement analysis method to familiarize with the product. In addition, system engineers can better distribute resources and confirm demands. Based on the architecture-oriented model for auto electrical products, demand analysis method can clearly integrated different aspects, including structural and behavioral. These statistics can be utilized in the following phases during project development, such as system design, production, testing, and proofing stages, especially where integration with software, electrical and structural system is important and complex for the development of auto electrical products. The architecture-oriented model can maintain consistency and can be traceable along with the requirements model.