Success in lean product realization depends on the ability to specify value from the voice of the customer at the beginning of the process. Value streaming, is therefore essential for assuring that the specified value is being pursued and achieved throughout the process. During lean implementation, however, it is usually assumed that nothing but value will be streamed if wastes are eliminated using value stream mapping. While waste elimination is necessary to make the process leaner and facilitate value streaming it is not sufficient for assuring that specified value is being streamed without structured and formalized participation of customers.With current structure of product realization processes, the voice of the customer is provided during the planning phase at the beginning of the process and customer satisfaction feedback is provided after product launch. With limited customer Participation during the process it is harder to assure that the voice of the customer specified value is being streamed. Shifting the process paradigm from planning, design, and manufacturing to the natural phases of inception, conception, and maturation would allow more structured and formalized participation of customers. Providing these necessary customers’ participations when needed would assure that specified value is pursued, streamed and ultimately achieved.In this paper an approach for assuring that the voice of the customer specified value is being streamed during traditional and lean product realization processes is discussed. For traditional product realization processes, value streaming and customer satisfaction could be greatly improved by structuring and formalizing customers’ evaluations of concept vehicles. For the lean product realization processes, value inputs start at the inception phase and value streaming continues through the product conception and development/validation. Participation of the customers is structured during formalized milestones to assure achievement of customers’ specified value.