Integrated product development is the future of product development. Integrated product development is a process where both upstream (e.g., functional requirements, styling and cosmetic features, and packaging) and downstream (e.g., manufacturing considerations, testing, dunnage, and disposal) requirements of a product are handled concurrently with its geometry construction. In this research, the so-called ECHO (Engineering Constraint Handling and Optimization) system for integrated product development has been developed. A unique feature of this system is that it can explicitly represent and process both the upstream and downstream requirements. These requirements are represented in the form of constraint networks, rule networks, and assessment matrices. By solving for all of the feasible solutions, the ECHO system instructs the geometry construction, and thus ensures that both upstream and downstream requirements are reflected in the design. A case study for automotive piston development has been implemented to illustrate the capability and use of the ECHO system.