A new CAE system has been developed for improving productivity and shortening delivery times of major assemblies such as engines and transmissions. This system provides precise information about production progress and actual workloads in each shop, making it possible to design the most suitable production process by simulation. Based on simulation results, work instructions can be directly to production workers via an information network. Similarly, in addition to work instructions and information on process design and management, the system also handles production requests and information about production conditions and delivery status -- all by electronic means without using paper. For small-lot production of mixed types of assemblies and components, this system makes it possible to increase flexibility, improve productivity and shorten delivery times.