Value stream: All the steps (both value-added and non-value-added) in a process
that bring a product or service through the flows essential to producing
that product or service. All activities, both value-added and non-value-added,
that are required to bring a product from raw material into the hands of the
customer, to fulfill a customer requirement from order to delivery, and to
complete a design from concept to launch. Value stream improvement usually
begins at the door-to-door level within a facility, and then expands outward
to eventually encompass the full value stream.